2009 Abstracts - Association for Chemoreception Sciences

AChemSAssociation for Chemoreception Sciences_________________________________________________________________________AChemS extends special thanks and appreciation forgrant support from:The National Institute on Deafness andOther Communications Disordersand theNational Institute on Aging, NIH_________________________________________________________________________The Association for Chemoreception Sciences is also grateful for thegenerous support of its corporate sponsors:Platinum SponsorsGold SponsorOther Sponsors_________________________________________________________________________A special thank you to Ghislaine Polak and the late Ernest Polakfor supporting the Polak Young Investigators Awards and theJunior Scientist Travel Awards._________________________________________________________________________The Association for Chemoreception Sciences thanks ourCorporate Members for their support.KNOSYS OLFACTOMETERS

AChemSAssociation for Chemoreception Sciences2009 Annual Meeting ExhibitorsOxford University PressOxford University Press publishes some of the world’s most respected books andjournals, including Chemical Senses. The journal publishes original research andreview papers on all aspects of chemoreception in both humans and animals.Please visit us online at www.oxfordjournals.org.Company Representative: Claire BirdSensonics, IncSensonics, Inc., manufactures and distributes quantitative smell and taste tests.The Smell Identification Test TM , has been translated into several languages andis the standard means for assessing olfactory function throughout the world.Visit www.sensonics.com for more information about our products and services.Company Representatives: Dr. Richard L. Doty and Paul MaroneSpringerSpringer is the proud publisher of Chemosensory Perception, now in its secondyear of publication, and recently accepted by ISI. Please stop by our booth to pickup a sample copy, as well as browse our books (available at the conference discount)and other journals. Susan Safren will be available to answer any questions aboutpublishing with Springer.Company Representative: Susan SafrenOsmic Enterprises, Inc.Osmic Enterprises, Inc. produces and distributes the OLFACT Test Battery,a series of computerized tests to assess olfactory function. Tests include a thresholdtest, an identification test, a discrimination test, and an odor memory test. Stimuliare generated via a miniature olfactometer, with administration of tests andrecording of responses under computer control.Company Representative: Kathleen VanDeGrift2009 Annual Meeting Exhibitors | 3

AChemSAssociation for Chemoreception Sciences2009 Awardees31st Annual Givaudan Lectureship - Givaudan CorporationCarla J. Shatz, Stanford University, Stanford, CA18th Annual Moskowitz Jacobs Award for Research in Psychophysics ofTaste and OlfactionJohan Lundström, Monell Chemical Senses Center16th Annual Ajinomoto Award to Promising Young Researcher in theField of GustationAlan Carleton, Brain Mind Institute, Ecole Polytechnique, Fédérale de LausanneInternational Flavors and Fragrances Award for Outstanding Researchon the Molecular Basis of TasteKeiko Abe, The University of TokyoMax Mozell Award for Outstanding Achievement in the Chemical SensesCharles Greer, Yale University School of MedicineThe AChemS Young Investigator Award for Research in OlfactionNathaniel Urban, Carnegie Mellon UniversityAChemS Distinguished Service AwardBarry Davis, National Institute of HealthThe Don Tucker Memorial Award (2008 Awardee)Aaron Beyerlein, University of ArizonaAChemS 2009 Logo Contest AwardMaria Veldhuizen, John B. Pierce Laboratory and Yale University School of MedicineThe Polak awards are funded by the Elsje Werner-Polak Memorial Fund inmemory of our niece gassed by the Nazis in 1944 at age 7: Ghislaine Polakand the late Ernest Polak2009 Polak Young Investigator Award Recipients:Wen Li, University of Wisconsin-MadisonNathalie Mandairon, Lyon UniversityIvan Manzini, University of GöttingenKoichi Matsumara, Monell Chemical Senses CenterArie Mobley, Department of Neurosurgery, Department of Neurobiology, Yale UniversitySharif Taha, University of Utah School of MedicineMaria Veldhuizen, John B. Pierce Laboratory and Yale University School of Medicine4 | AChemS Abstracts 2009

We are pleased to announce that five 2009 Polak Junior Scientist Travel Awardswere given for this year’s meeting.AChemS Minority/Travel Fellowship RecipientsFunded by a generous grant from the National Institute on Deafness andOther Communication Disorders and the National Institute on Aging, NIHJuan Aggio, Georgia State UniversityC. Shawn Dotson, University of Maryland School of MedicineWombura Fobbs, John B. Pierce Laboratory and Yale University School of MedicineKristina Gonzalez, Clark UniversityErnesto Salcedo, University of Colorado DenverNhat-Tuan Tran, University of Colorado DenverRobert Utsman, University of MinnesotaAChemS Student Housing and Travel Award RecipientsFunded by the Polak Foundation: Ghislaine Polak and the late Ernest PolakLindsey Silz Rebekka Zernecke Honghong ZhangRichard Krolewski Sara Dudgeon Andrew RosenAdam Packard Johanna Spitzer Alexandra MillerAllana Goodman Amanda Elson Kristin RudengaKrystin Corby Sebastian Rasche Julie BoyleFaye Pesenti Amy Gordon Markus RothermelAnna Kleeman Lian Gelis Sabrina BaumgartApril Glatt Matthias Luebbert Silke HagendorfChun Yang Debbie Radtke Jeremy McIntyreKaeli Samson Masashi Tabuchi Dorothee BuschhuterSamsudeen Ponissery2009 Awardees | 5

AChemSAssociation for Chemoreception SciencesCommitteesAChemS Executive Committee 2008-2009President Peter Brunjes, PhD University of VirginiaPast President Diego Restrepo, PhD University of ColoradoSenior Advisor Leslie Tolbert, PhD University of ArizonaPresident Elect Scott Herness, PhD Ohio State UniversitySecretary Dana Small, PhD JB Pierce Laboratory/YaleUniversity Membership Chair Pamela Dalton, PhD Monell Chemical Senses CenterProgram Chair Don Wilson, PhD Nathan Kline Institute &NYU School of MedicineTreasurer Carol Christensen, PhD Monell Chemical Senses CenterJr. Councilor Lynette Phillips McCluskey, PhD Medical College of GeorgiaSr. Councilor Nirupa Chaudhari, PhD University of MiamiProgram Chair Elect Robert Margolskee, PhD Mount Sinai School of MedicineAChemS Program Committee 2008-2009Don Wilson Robert Lane Chris LemonBeverly Tepper Robin Krimm Helen TreloarTom Finger Noam Sobel Minghong MaKevin Kelliher Kazushige Touhara Leslie VosshallAlan Nighorn Harriett Baker Paul MooreSteve MungerCatherine RoubyMEETING EVALUATIONThe meeting evaluation is available online this year. Please visit www.achems.org after the meetingto give us your feedback on the meeting. A reminder email will be sent. Your input helps AChemS’leadership continue to offer quality annual meetings and member services.6 | AChemS Abstracts 2009

#1 Givaudan LectureTuning up Circuits: Brain Waves, Immune Genes andSynapse PlasticityCarla J. ShatzStanford University Stanford, CA, USAConnections in adult brain are precise, but they do not start outthat way. Precision emerges in development as synapticconnections remodel, a process requiring neural activity andinvolving regression of some synapses and strengthening andstabilization of others. Neural activity also regulates neuronalgenes; in an unbiased PCR-based differential screen, we made theunexpected discovery that MHC Class I genes are expressed inneurons and are upregulated by neural activity and visualexperience (Corriveau et al, 1998; Goddard et al, 2007). To assessrequirements for MHCI in CNS, mice lacking expression ofMHCI were examined. Synapse regression in the developingvisual system did not occur and in adult hippocampus synapticstrengthening was greater than normal (Huh et al, 2000),suggesting that MHCI may function in synaptic plasticity.Receptors for neuronal MHCI could carry out these activitydependentsynaptic processes. In a systematic search, PirB, aninnate immune receptor, was found to be highly expressed inCNS neurons. Mutant mice lacking PirB function have increasedplasticity in visual cortex (Syken et al., 2006), as well as increasedsynaptic strengthening (LTP) in hippocampus. Thus PirB, likeMHCI, appears to function as a “brake” on synaptic plasticity inthe CNS. Together, results imply that this family of molecules,thought previously to function only in the immune system, mayalso act at neuronal synapses to limit how much- or perhaps howquickly- synapse strength changes in response to new experience.These molecules may be crucial for controlling circuit excitabilityand stability in developing as well as adult brain. Supported byNIH Grants EY02858, MH071666, Mathers CharitableFoundation, Dana Foundation.#2 GustationWnt/ß-catenin Signaling Controls Taste Bud Regenerationin MiceLinda A. Barlow 1 , Fei Liu 2 , Shoba Thirumangalathu 1 ,Elizabeth A. Harvey 1 , Ping Wu 1 , Sarah E. Millar 31Department of Cell and Developmental Biology & RockyMountain Taste & Smell Center, University of Colorado Denver,School of Medicine Aurora, CO, USA, 2 Institute for RegenerativeMedicine at Scott & White Hospital, Texas A&M UniversitySystem Health Science Center Temple, TX, USA, 3 Departments ofDermatology and Cell and Developmental Biology, University ofPennsylvania School of Medicine Philadelphia, PA, USATaste buds are renewed throughout life such that each of the~3 cell types is continually replenished. However, the molecularmechanisms controlling this process are not understood. BecauseWnt/ß-catenin signaling is a key regulator of embryonic taste buddevelopment (Liu et al. 2007; Iwatsuki et al. 2007) we tested therole of this pathway in adult taste cell turnover. Using severalindependent mouse lines that report Wnt/ß-catenin signal, wediscovered that many cells within fungiform and circumvallatetaste buds are Wnt-responsive. Double immunostaining forseveral differentiated taste cell markers revealed that virtually allWnt activation in fungiform taste buds occurs in NTPDase2-IRtype I cells, while in circumvallate papilla, type I and serotonin-IRtype III cells are also Wnt-responsive. To determine the functionsof Wnt/ß-catenin in taste buds, we used tetracycline induciblesystems to either force activation of Wnt/ß-catenin (ac-ßcat) orectopically express Dkk1, a secreted Wnt inhibitor, in the lingualepithelium of adult mice. After a 2 week drug treatment to inducethe transgene, the tongue surface of ac-ßcat mice appearedpebbled, and in sections, both fungiform papilla size and thenumber of taste bud-like cell clusters within each papilla wereincreased. Using taste cell type specific immunomarkers, wefound that the excess taste cell clusters comprise only type I cells,with no increase in types II or III. By contrast, all 3 cell typeswere affected in taste buds of Dkk1 overexpressing mice; types IIand III were completely lost, and only a few abnormal type I cellsremained. We now hypothesize that Wnt signaling is sufficient todrive type I cell differentiation and that Wnt-supported type Icells are required for maintenance of type II and III cells.#3 GustationFatty acids induce increases in intracellular calcium inType II and a subset of Type III mouse taste cellsPin Liu, Bhavik Shah, Hala Hadawar, Timothy GilbertsonDepartment of Biology and The Center for Advanced Nutrition,Utah State University Logan, UT, USAObesity has been shown to be driven, as least in part, by increasesin dietary fat intake. Thus, it is important to understand theunderlying mechanisms that our body uses to recognize dietaryfat. In recent years, a number of studies have demonstrated theability of components in fats, specifically free fatty acids (FFAs),to activate taste bud cells (TBCs) and elicit behavioral responsesconsistent with there being a taste of fat. Recently, we have usedfura-2 based calcium imaging to explore the ability of FFAs toelicit intracellular calcium ([Ca 2+ ] i ) rise in isolated C57BL/6TBCs. Our data show that FFAs (1-100 µM) elicit robustincreases in [Ca 2+ ] i in approximately 20% of circumvallate TBCs,and 35% of fungiform TBCs. To identify the subtype of FAresponsiveTBCs, we have used responses to high KCl solutionsas an indicator of type III (presynaptic) cells and responses to atastant mixture (sweet/bitter/umami) to identify type II (tastereceptor) cells. FFAs are primarily able to elicit intracellular Ca 2+responses in cells that correspond to Type II cells, however, asmall but significant subpopulation of Type III cells also respondto FFAs. Surprisingly, a small number of TBCs responded to allthe solutions tested, including high KCl, the tastant mixture andFFAs. This finding questions the utility of being able to use thesesolutions to identify unequivocally subtypes of cells within thetaste bud. Transgenic mice expressing enhanced green fluorescentprotein (GFP) under control of the PLCbeta2 promoter(PLCbeta2–GFP) were also used to verify the data showing FFAresponsiveness occurs primarily in Type II cells. A model for thetransduction of FFAs in TBCs consistent with these findings andour previous data will be presented.Abstracts | 7

#4 GustationGPR40 knockout mice have diminished taste responsesto fatty acidsSami Damak 1 , Cristina Cartoni 1 , Keiko Yasumatsu 2 ,Johannes le Coutre 1 , Yuzo Ninomiya 21Nestlé Research Center Lausanne, Switzerland, 2 KyushuUniversity Fukuoka, JapanThe perception of dietary fat is based mainly on texture, viscosityand olfaction, but there is increasing evidence that the taste systemalso plays a role. Triglycerides, the main components of oils andother dietary fats are hydrolyzed by the lingual lipase into freefatty acids, which are detected by the gustatory system. GPR40and GPR120 are G-protein coupled receptors (GPCRs) thatrespond to medium and long chain fatty acids. Byimmunohistochemistry, we showed that both GPCRs areexpressed in mouse taste cells. GPR120 is expressed incircumvallate, foliate and fungiform papillae, mainly in type IIcells. GPR40 is expressed in circumvallate and foliate but veryrarely in fungiform papillae, mainly in type I cells. To determine ifGPR40 plays a role in fat taste signal transduction, we carried outbehavioral and nerve recording studies on GPR40 knockoutmice. Compared with control mice, GPR40 knockout mice havediminished preference and intake for intralipid, oleic acid, linoleicacid and lauric acid. Glossopharyngeal whole nerve recordingsshowed a diminished response to lingual application of lauric acid,oleic acid, linoleic acid, linolenic acid and DHA. The GPR40knockouts showed residual behavioral and electrophysiologicalresponses to fatty acids and oils. These data show that GPR40 is afat taste receptor, but other receptors and/or pathways mustexist. The residual response of GPR40 knockout mice to lipidsmay be accounted for by other signaling molecules such as CD36,DRK or GPR120.#5 GustationThermal taste: association with perception of oralsensations and food and beverage behaviorMartha R Bajec, Gary J PickeringBrock University St Catharines, ON, CanadaFood/beverage flavor and liking strongly influence consumption,and consequently a range of nutritional and health outcomes.Thus, variation in perception of chemosensory stimuli, whichform the flavor construct, can influence habitual dietary intakeand risk of chronic diet-related disease (Duffy et al 2008).Arguably, the most important factor explaining differences inperception of chemosensory stimuli is genetic variation.Sensitivity to phenylthiocarbamide (PTC) and 6-npropylthiouracil(PROP) has long been proposed as a geneticallymediated correlate of some food behaviors. More recently, a newsource of individual differences in oral sensation was identified:thermal taster status (TTS; Cruz and Green 2000). Thermal tasters(TTs), who may constitute up to 50% of the population, perceivephantom tastes when small areas of the tongue are heated orcooled. The phenomenon is linked to the TRPM5 cation channel(Talavera et al 2005). We investigated the hypothesis that (i)TTS predicts responsiveness to multiple oral sensations, and (ii)TTS associates with liking of food/beverages. 73 subjects wereclassified as TTs or thermal non-tasters (TnTs), and rated theintensity of a range of prototypical taste and other oral stimuliusing the gLMS. Subjects also rated liking – a proxy forconsumption (Duffy et al 2008) – of 301 food and 61 beverageitems, including 43 alcoholic products, using a 7-point hedonicscale. TTs rated most taste and trigeminal stimuli as significantlymore intense than TnTs (ANOVA; p(F)

Chorda tympani (CT) anesthesia leads to elevatedglossopharyngeal (IX) sensation; among supertasters of 6-npropylthiouracil,it also enhances trigeminal (V) sensation. Thesefindings imply that oral disinhibition occurs in proportion togenetic taste status, and that affected sensations are differentiallysusceptible to these effects. Supporting this idea, in healthysubjects with low taste function, unilateral anesthesia of either thelingual nerve (i.e., CT and V; N = 46) or the chorda tympani (N =28) asymmetrically compromises posterior taste sensation, withthe side contralateral to anesthesia showing the least suppression.Lingual nerve block produced posterior asymmetry for all fourcommon taste modalities, but direct CT block did so only forsalty stimuli. Previous reports suggest that loss of 2+ oral sensoryinputs broadly compromises taste function; these reports alsoshow posterior taste enhancement with CT block, but modalityspecificasymmetry may represent mild disinhibition inindividuals with low native taste function. Finally, contralateralanterior oral burn remained intact with both nerve blocks, whileposterior oral burn was blunted bilaterally; these data imply thatdisinhibitory trigeminal enhancement is associated with hightaster status. In sum, disinhibitory effects of localized oral sensoryloss vary based on genetic taste status; posterior taste elevationmanifests in nontasters as asymmetric loss, while trigeminaleffects occur mainly in supertasters.#8 Withdrawn#9 Gustation“Restrained Eaters” Show Abnormal and DifferentialfMRI Activation to Sucrose and SaccharinClaire Murphy 1,2 , Nobuko Kemmotsu 1,21San Diego State University San Diego, CA, USA,2University of California, San Diego San Diego, CA, USAObesity in the US has reached epidemic proportions, affectingpresent and future health status of millions of Americans. Personswho exercise cognitive restraint over eating behavior may provideinsights into underlying mechanisms of obesity. “Restrainedeaters” attempt to control weight by cognitive restraint, activelyregulating the quantity and quality of food intake. Whether theyhave altered brain activity to nutritive and non -nutritive tastestimuli is unknown. The present study investigated tasteinformation processing in the central nervous system using thefunctional MRI technique. Sixteen participants were “restrainedeaters” defined by Factor 1 (cognitive restraint) items of the ThreeFactor Eating Questionnaire (TFEQ; Stunkard & Messick, 1985),and 16 were “non-restrained eaters.” The BOLD signal changewas investigated when the participants were hungry and satiatedwith a nutritional preload, in response to sucrose and saccharin.Non-restrained eaters responded with more robust activation tothe caloric sweetener. In contrast, the restrained eaters showed adifferent activation pattern, demonstrating greater response tosaccharin than to sucrose. Interestingly, restrained eaters showeddecreased activation in OFC and amygdala in response to thesaccharin when satiated, the same pattern observed in thenon-restrained eaters in response to sucrose. This differentialactivation to sucrose and saccharin, particularly in reward areas ofthe brain, suggests altered brain mechanisms in restrained eaters.A better understanding of the development and maintenance ofthis phenomenon may lead to strategies for prevention of andinterventions for obesity.#10 Gender effects on olfactory processingAxons of gustatory receptor 32a expressing neurons extendtheir terminal throughout adult lifetimeTetsuya Miyamoto, Hubert AmreinDepartment of Molecular Genetics and Microbiology,Duke University Medical CenterCourtship is an essential behavior for successful mating. In maleDrosophila, chemosensory cues are thought to control manyaspects of courtship such as identification of partners of the samespecies, appropriate sex and suitable mating status. Recently,we report that the gustatory receptor (Gr) gene, Gr32a, plays animportant role in male courtship. Gr32a mutant males shownormal courtship towards females. However, the courtship indexof Gr32a mutant males towards males and mated females, whichcontain male pheromones, is much higher than that of wild typemales. These results indicate that Gr32a is essential for detectionof a male inhibitory pheromone, which is necessary forsuppression of courtship towards unrewarding potential mates.Gr32a is expressed in chemosensory neurons of labial palp andlegs, but leg neurons are sufficient to repress male-male courtship.All gustatory neurons are thought to project to the primary tasteprocessingcenter, subesophageal ganglion. However, weoccasionally observed that Gr32a leg neurons directly project tothe ventro-lateral protocerebrum, which is known as a higherorder brain structure as receiving input from multiple sensorymodalities, including visual, auditory, and possibly olfactorycues. The morphology of Gr32a neurons outside of thesubesophageal ganglion shows a huge diversity among individualand even in either side of the same brain. Their axon ends atvarious positions, from the subesophageal ganglion to upper endof the ventro-lateral protocerebrum. The number of axon terminalis also widely ranged, from 1 to 20. Strikingly, there is a clearcorrelation among the probability of axon to reach the ventrolateralprotocerebrum, the complexity of axon terminal and age upto 60 days after eclosion. This is also observed in flies kept inisolation, though less significant than that of flies kept in a group.Our studies suggest Gr32a leg neurons slowly extend theirterminals throughout adult lifetime; this phenomenon might leadolder, socially experienced flies tend to avoid males and matedfemales more strictly.#11 Gender effects on olfactory processingRecognition of Sexual Cues in the Urine byMouse Vomeronasal OrganRon Yu 1,2 , Jie He 1 , Limei Ma 1 , Sangseong Kim 1 , Junichi Nakai 31Stowers Institute Kansas City, MO, USA, 2 University of KansasMedical Center Kansas City, KS, USA, 3 RIKEN Brain InstituteWako-shi, JapanThe vomeronasal organs of the mammalian species detect complexchemical signals in the urine that convey information about sex,strain, as well as the social and reproductive status of anindividual. How such complex signals are recognized by thevomeronasal organ is not well understood. In this study, we havedeveloped transgenic mice expressing the calcium indicator,G-CaMP2, to analyze the population response of vomeronasalneurons to urine from individual animals. We found that asubstantial portion of the cells were activated by either male urineor female urine, but most of them contributed little to sexdiscrimination. Sex information was represented by a surprisinglyAbstracts | 9

small population of cells responding exclusively to sex-specificcues shared across strains and individuals. Female-specific cuesactivated more cells and were subject to more complex hormonalregulations than male-specific cues. In contrast to sex, strain andindividual information contained in urine was encoded by thecombinatorial activation of neurons such that urine samples fromdifferent individuals elicited distinctive patterns of activation.Interestingly, mouse urine at different concentrations activatesdistinct subsets of VNO neurons. Direct investigation of theurogenital area allows pheromones to reach the VNO at a levelthat provides unambiguous identification of the sex and the strainof animals. Lower concentration urine activates a different set ofcells, some of which are masked by high concentration urine.These observations suggest that the vomeronasal circuitry is likelyto perform complex computation of pheromone information in acontext-dependent manner to trigger innate behaviors andendocrine changes.#12 Gender effects on olfactory processingVomeronasal reception of a sex peptide pheromoneESP1 in mice: the receptor, neural circuitry, and behaviorKazushige TouharaDepartment of Integrated Biosciences, The University of TokyoChiba, JapanWe have previously discovered a male-specific putativepheromone, exocrine gland-secreting peptide 1 (ESP1), that isreleased into tear fluids from the extraorbital lacrimal gland andactivates vomeronasal sensory neurons in female mice. Here weshow the identification of a specific vomeronasal receptor V2Rp5for ESP1 and the involvement of TRPC2 in its downstream signaltransduction mechanism. The neural pathway beginning with aspecific recognition of ESP1 by V2Rp5 was visualized, showingthe transmission of the ESP1 signal to the spatially highlyorganizedpopulation of secondary neurons in the accessoryolfactory bulb. ESP1 induced a sexually dimorphic activationpattern at higher-order brain regions. We observed theinvolvement of ESP1 in a sexual behavior of female mice.Together, we demonstrate that the “labeled-line” pathwayfrom a specific receptor to the brain in a sex-specific manneris a molecular and neural basis for the vomeronasal system thatdecodes and represents information of a sex peptide pheromone.The present study provides molecular and functional linkbetween a sex peptide pheromone and a selective neuralcircuitry leading to a behavioral output via a specific receptorin the mouse vomeronasal system.10 | AChemS Abstracts 2009#13 Gender effects on olfactory processingDifferential Sensory Neuron Activation Underlies GenderDimorphic Aggressive BehaviorLisa Stowers 1 , Pablo Chamero 2 , Kelly Flanagan 1 , Fabio Papes 3 ,Darren DW Logan 1 , Toby F Marton 4 , Angeldeep Kaur 11The Scripps Research Institute La Jolla, CA, USA, 2 Universityof Saarland Homberg, Germany, 3 State University of CampinasCampinas, Brazil, 4 University of California San Diego San Diego,CA, USAFemales do not respond aggressively to the same pheromones thatprovoke aggression in males. The underlying neural code thatresults in this gender dimorphic behavior is unknown. Moleculardifferences in the sensory neurons between male and female micehave not been reported. Recent findings in Drosophila haveshown that each gender detects the ligands similarly and knowndifferences in the organization of the responsive neural circuitsmay lead to their differing innate behaviors (Datta et al., 2008).We now show that while neurons in the male vomeronasal organare activated in response to MUPs, female sensory neurons aredramatically impaired to all but one identified MUP suggestinga sensory perception difference between males and females.Interestingly, females do not robustly detect the individual MUPthat promotes aggression in males. The dimorphic sensoryresponse is not genetic but rather a response to female hormonesas juveniles of both sexes and castrated males detect all Mupssimilarly to intact males with the response extinguishing asfemales become sexually mature. This response is plastic andrapid; manipulating hormone levels in females leads to acorresponding change in the ability of vomeronasal neurons todetect and respond to Mups. The lack of response to theaggression MUP pheromone by females singularly provides anovel mechanism for this innate gender dimorphism.#14 Gender effects on olfactory processingOpposite-sex volatile urinary odors detected by the mainand processed via the accessory olfactory system contributeto mate recognition in miceMichael J. Baum 1 , Ningdong Kang 1 , Kristine M. Martel 1 ,James A. Cherry 21Dept. of Biology, Boston University Boston, MA, USA,2Dept. of Psychology, Boston University Boston, MA, USAWe assessed the contribution of main and accessory olfactorysignaling to the preference of mice to investigate opposite- versussame-sex urinary odors. Urinary volatiles from the 2 sexesstimulated distinct profiles of glomerular activation in the ventralmain olfactory bulb (MOB) of both male and female mice.By contrast, only opposite-sex urinary volatiles stimulatedFos expression in the accessory olfactory bulb (AOB) after theirdetection by the main olfactory epithelium (MOE) as opposed tothe vomeronasal organ. Tract tracing experiments in female miceshowed that urinary odors from opposite-, but not same-sex,conspecifics stimulated Fos expression in MOB mitral/tuftedcells that project directly to the ‘vomeronasal’ (medial) amygdala.Opposite-sex urinary volatiles also selectively stimulated Fosexpression in medial amygdalar neurons that send centrifugalprojections to the AOB of females. Bilateral AOB lesions in eithermale or female mice attenuated subjects’ motivation to investigateopposite-sex urinary volatiles. Opposite-sex urinary volatilesthat are initially detected by the main olfactory system gainpreferential access to the vomeronasal amygdala and theAOB with a resulting facilitation of mate recognition andreproductive success. Supported by NIH grant HD 044897.

#15 Gender effects on olfactory processingNeural control of sexually dimorphic behaviorsNirao ShahUCSF San Franciscio, CA, USASex specific behaviors such as mating and aggression are innatebehaviors in mice as they can be displayed without prior trainingor experience. Nevertheless, these behaviors are tightly regulatedby pheromones as well as by sex steroid hormones. We willpresent data demonstrating distinct sensory and hormonalcontrol of these behaviors.#16 Presidential Symposium: On beyond glomeruliFunctional Architecture of Inhibition in the Olfactory Bulb:Glomeruli and BeyondMichael T ShipleyDepartment of Anatomy & Neurobiology, Program inNeuroscience University of Maryland School of MedicineBaltimore, MD, USASensory inputs are transformed to outputs via mitral and tufted(MT) cell projections to olfactory cortex (POC). Inhibitionshapes this transformation at two levels: Glomerular circuitsmediate presynaptic inhibition of olfactory nerve (ON) terminalsand postsynaptic inhibition of MT apical dendrites.Infraglomerular circuits exert postsynaptic inhibition at MTlateral dendrites. Glomerular circuits: Two intraglomerularglomerular circuits operate on single glomeruli to mediatetonic/phasic and pre-/postsynaptic inhibition. Interglomerularcircuits enhance contrast among hundreds of distant glomeruliand multiglomerular circuits link smaller groups of neighboringglomeruli roughly the size of ‘modules’ responsive to structurallysimilar odors. Glomerular circuits lack POC feedback butcentrifugal modulatory inputs (5HT, ACh) strongly shapepre- and postsynaptic inhibition. Infraglomerular circuits:MTs reciprocally synapse with granule cells (GC), which mediaterecurrent and lateral inhibition of MTs. Infraglomerular circuitsare targeted by central modulatory inputs (5HT, ACh, NE).They receive massive cortical inputs, which excite GCs thusinhibiting MTs. How do these inhibitory circuits shape olfactoryprocessing? Modulatory inputs provide behavioral statedependent regulation of both glomerular and infraglomerularcircuits. Glomerular circuits are driven by sensory signals. Theyfollow repetitive ON inputs and exert more powerful inhibitionof MTs than previously thought. They temporally sharpen MTfiring and maintain contrast among glomerular outputs acrossdynamic changes in odor concentration. Infraglomerular circuitsare strongly influenced by cortical feedback, which may regulatechanges in MT firing across sniff cycles. Cortical feedback maymediate experience-dependent plasticity.#17 Presidential Symposium: On beyond glomeruliOlfactory systems theoryThomas A. Cleland 1 , Christiane Linster 21Dept. Psychology, Cornell University Ithaca, NY, USA, 2 Dept.Neurobiology & Behavior, Cornell University Ithaca, NY, USAThe idea that glomerular activation patterns underlie odorperception and recognition is analogous to claiming that theinverted image maps of photoreceptor activation identify visualobjects; that is, the statement is not clearly wrong, but missesnearly the entirety of the problem. As with any sensory system,the olfactory receptor neuron layer serves the primary purposeof transducing environmental variance into profiles of neuralactivity. The resulting primary representations are degenerate,occluded, and naïve reflections of the odor environment;nominally identical stimuli emit variable odor signatures,unpredictable mixture elements and background odorsirreversibly interfere with the replicability of receptor activationprofiles, and there exists no clear means to distinguish importantfrom random sources of sensory variance. Meaningful perceptualinformation must be constructed from this pool of structuredvariance by the neural circuitry of the olfactory bulb (OB) and themultiple secondary structures to which it projects. We will outlinethe computational problems faced by the olfactory system anddescribe models for how the architectures of its successive layersof neuronal processing contribute to their resolution. Particularattention will be paid to the analogous problems faced by othersensory systems, as well as the differences between them, and tothe role of memory in olfactory perception. Expanding upon ahistory of comparing the OB to the retina, we propose that anamalgam of the retina and primary visual cortex (V1) is a moreappropriate visual-system analogy for OB function.#18 Presidential Symposium: On beyond glomeruliOscillatory Modes and the Role of Task Structure inEarly Olfactory ProcessingLeslie M. KayDepartment of Psychology and Institute for Mind & Biology,The University of Chicago Chicago, IL, USAEarly stages of processing in the olfactory system are oftenconsidered to consist of relatively static mechanisms, dictated byglomerular input patterns, with minor adjustments related tointensity of the input signal and modulation of its strength bycentral processes. More recently, it has been shown by my lab andothers that changes in the temporal precision of mitral cells,signified by the gamma oscillation of the local field potential, arerelated to processing highly overlapping odorant input patterns.Recent work from my laboratory shows that gamma oscillationsare modified dependent on task demands. However, we have alsoshown that the structure of the task used to determine odoridentification can influence the type of oscillatory mode, theinvolvement of central brain areas in primary odor processing,and the difficulty of the discrimination itself. We show thatchanging the task from a two-alternative choice to a go/no-go taskalters the way in which the olfactory bulb, piriform cortex andhippocampus participate in odor processing. The oscillatorysignature changes from a gamma oscillation local to the olfactorybulb, to a beta oscillation that is coherent with activity in theseAbstracts | 11

higher order areas. The beta oscillation mode is thus not just adifferent frequency but a different network. This larger and moredistributed network is associated with more flexibility in learningodor associations.#19 Presidential Symposium: On beyond glomeruliRostral Olfactory CortexKurt R. IlligUniversity of Virginia Charlottesville, VA, USAIn mammals, several cortical areas receive direct input from theolfactory bulb. Although in some species these areas can comprise10% of total cortical volume, fundamental questions remainregarding their role in olfactory information processing. In thispresentation, I will consider the circuitry and function of therostral olfactory cortical structures, and examine how theseregions may contribute to olfaction and odor-guided behavior.#20 Presidential Symposium: On beyond glomeruliOlfaction in the wider world: The cortex and beyondJoel PriceWashington University at St. LouisThe olfactory bulb projects through the lateral olfactory tractonto at least seven “primary” olfactory cortical areas. Althougha topographic organization has not been identified, the cortex isdominated by “association” connections from several of theolfactory cortical areas that match the bulbar projection.Throughout the olfactory cortex the fibers from the olfactorybulb end on dendrites in the superficial lamina of layer I, whileassociation fibers end on precisely complementary parts of thesame dendrites, and in deeper parts of the cortex. This providesa mechanism for cortex-wide integration of the informationcoming out of the bulb that is presumably the basis for olfactorydiscrimination. Many of the olfactory areas send axons intoisocortical areas in the caudal orbital and rostral insular cortex.Although these areas could be considered “higher order”olfactory cortex, they are substantially interconnected withadjacent areas in the orbital cortex that receive taste, visceral,visual and somatic sensory inputs. It appears that these areasintegrate olfactory information with other modalities to provideassessment of flavor and other characteristics of food includingappearance and texture. In addition, this cortex codes for rewardor value as well as sensory aspects of the stimuli.#21 through #27 Development and Plasticity:First Central Chemosensory RelaysDevelopment and Plasticity:First Central Chemosensory RelaysCharlotte M. Mistretta 1 , David L. Hill 21University of Michigan Ann Arbor, MI, USA,2University of Virginia Charlottesville, VA, USAThere is little information about the nature, timing and extent ofdynamic processes that establish and maintain functional centralnuclei in chemosensation. Formation of functional groups duringdevelopment requires timed waves of neuron birth, migration, anddifferentiation. Neuron clusters then attract and receive sensoryinput that often dramatically reorganizes the maturing circuit.With data from moth, lobster, chick and rodent, across taste,olfactory and respiratory systems, we will explore how neuronsinitially come to cluster and receive specific sensory input, andunderstand feats of plasticity in central chemosensation. The focusis on the first central afferent relays of three systems. After anintroductory talk with general principles and mechanisms, therewill be three short talks with specific examples of early nucleusdevelopment. Then two concluding talks will emphasize plasticityin sensory relay nuclei in developing rostral and caudal rodentbrainstem. The symposium will stimulate development of newideas and questions about formation of chemosensory nuclei —highly plastic central regions. C. Krull, University of Michigan.Mechanisms to establish functional groups of neurons: Lessonsfrom chick neurogenesis. L. Oland, University of Arizona.Roles for glia in regulating formation of neuronal groups in motholfactory lobe. M. Schmidt, Georgia Sate University. Long lifeexpansion of olfactory brain in spiny lobster by neurogenesis.R. Bradley, University of Michigan. Establishing the rat tastenucleus of solitary tract (NST): A. Erisir, University of Virginia.Development and plasticity of neuron and synapse morphologyin rat rostral NST. D. Kunze, Case Western Reserve University.Plasticity in synaptic function following altered chemosensoryinput to caudal NST.#28 Polak Young Investigator Award WinnersNucleotide-mediated signaling in the olfactory epitheliumIvan Manzini 1,2 , Thomas Hassenklöver 1,2 , Silvia Kurtanska 1 ,Stephan Junek 1 , Ilonka Bartoszek 1 , Detlev Schild 1,21University of Göttingen Göttingen, Germany, 2 DFG ResearchCenter for Molecular Physiology of the Brain (CMPB) Göttingen,GermanyExtracellular nucleotides are important signaling moleculesthat mediate various biological effects via cell-surface receptorstermed purinergic receptors. Here we employed functionalcalcium imaging in acute slice preparations of the olfactoryepithelium (OE) to investigate the effect of extracellularnucleotides on the different epithelial cell types of larval Xenopuslaevis. Nucleotides evoked distinct increases in the intracellularcalcium concentration [Ca 2+ ] i in sustentacular cells (SCs) andbasal cells (BCs), the olfactory stem cells of the OE, but not inolfactory receptor neurons. Thereby we were able to show thatnucleotides elicit intracellular calcium waves in SCs. The wavesinitiate in the apical part of the SCs and propagate towards theirendfeet in the basal part of the OE (wave velocity 17.10 ± 1.02µm/s). The characteristic increases in [Ca 2+ ] i could be evoked in12 | AChemS Abstracts 2009

#34 Reciprocal interactions between primarytaste and olfactory processing networksand higher cognitionTop-down Modulatory Influences on Central Encoding ofTaste and Flavor in HumansDana Small 1,21The John B Pierce Laboratory New Haven, CT, USA,2Yale University New Haven, CT, USAPerception of taste, smell and flavor depends upon a multitude offactors other than the physiochemical properties of the stimulus.Recent work from our, and other laboratories, has demonstratedthat top-down processes related to selective and directedattention, expectation, and belief modulate BOLD response totaste throughout the gustatory network and beyond. For example,trying to taste in the absence of taste activates insular taste cortexand this same region responds preferentially to the same tastewhen it is unexpected compared to when it is expected. Theinsular taste cortex also shows preferential connectivity with theamygdala when subjects taste passively compared to when theyare asked to perform a task. This suggests that informationtransfer between the insula and amygdala is maximal duringimplicit processing of taste. In contrast, when subjects attend toand make judgements about taste pleasantness the insula ispreferentially connected to the lateral orbitofrontal cortex. Thisfinding highlights the importance of information transfer betweenthe insula and the orbitofrontal cortex during explicit hedonicevaluations. Beyond the canonical gustatory network, more recentwork in our lab has demonstrated that information aboutmarketing labels influences activity in brain regions regulatingenergy balance, and that such influence strongly and secificallydepends on individual variations in sensitivity to reward.Taken together these data highlight the importanceof top-downmodulatory influences on central encoding of taste and flavorin humans.#35 Reciprocal interactions between primarytaste and olfactory processing networksand higher cognitionRoles of cognition and attention in the neural processing oftaste and odorEdmund RollsOxford Centre for Computational NeuroscienceHow cognition and attention influence the affective brainrepresentations of the taste, flavor, and smell is important notonly for understanding top-down influences on multisensoryrepresentations in the brain, but also for understanding how tasteand flavor can be influenced by these top-down signals. We foundusing functional magnetic resonance imaging that activationsrelated to the affective value of umami taste and flavor (as shownby correlations with pleasantness ratings) in the orbitofrontalcortex were modulated by word-level descriptors, such as“rich delicious flavor”. Affect-related activations to taste weremodulated in a region that receives from the orbitofrontal cortex,the pregenual cingulate cortex, and to taste and flavor in anotherregion that receives from the orbitofrontal cortex, the ventralstriatum. Affect-related cognitive modulations were not found inthe insular taste cortex, where the intensity but not thepleasantness of the taste was represented. Moreover, in a differentinvestigation, paying attention to affective value (pleasantness)increased activations to taste in the orbitofrontal and pregenualcingulate cortex, and to intensity in the insular taste cortex.We conclude that top-down language-level cognitive effectsreach far down into the earliest cortical areas that represent theappetitive value of taste and flavor. This is an important way inwhich cognition influences the neural mechanisms of taste, flavor,and smell, and that control appetite.#36 Reciprocal interactions between primarytaste and olfactory processing networksand higher cognitionCognitive influences on taste processing in the gustatorycortex, orbitofrontal cortex and amygdalaAlfredo FontaniniDepartment of Neurobiology and Behavior, SUNY Stony BrookStony Brook , NY, USATaste, often thought of as the start of an ingestive process, is infact the outcome of a sequence of anticipatory behaviors naturallyguided by cues from other sensory modalities. These cues, besidesguiding action, promote expectations which can influence the waygustatory stimuli are perceived. Recent experiments show thatwhen human subjects adjust their perception according toexpectations the patterns of activation of their gustatory brainvary accordingly. However, it is not known how single gustatorycortical neurons change their dynamics and what the source ofthis modulatory input is. Anatomical evidence of a stronginterconnectivity with gustatory cortex suggests a possibleinvolvement of regions known to process anticipatory cues, likeamygdala and orbitofrontal cortex. In this seminar I will talkabout how the expectation of incoming taste stimuli modulatesneural activity in simultaneously recorded sensory and high orderbrain areas of rats. I will present data recorded simultaneouslyfrom taste cortex, orbitofrontal cortex and the amygdala, and Iwill compare single neuron responses to taste stimuli that wereeither presented unexpectedly or were self-administered followinga tone cue (and were therefore expected). The differences betweenthese two conditions will be discussed with a particular emphasison the emergence in all recorded areas – including the gustatorycortex — of tone responses. In lights of these results, I will discussthe relationship between expectation and the processing of tastesand highlight evidence for the role of high order areas inmodulating gustatory cortical activity.#37 Reciprocal interactions between primarytaste and olfactory processing networksand higher cognitionThe piriform cortex plays an active role in olfactory-guideddecision makingLinda Hermer-VazquezUniversity of Florida, Center for Smell and Taste Gainesville, FL,USAThe discreet nature of sniffing provides advantages forinvestigating the roles of sensory and motor cortices in highercognitive processes such as decision making. Several recentexperiments have called into question the long-held assumptionthat decision-making occurs as a tripartite, hierarchical process,with sensory recognition followed by prefrontal-based decisionmaking,and then when appropriate, motor output, with theAbstracts | 15

conclusions limited, however, by the type of task used,insufficiently high spatial or temporal resolution, or the lack ofmore advanced signal analysis. Here I will present a line of workindicating that the olfactory cortex directly influences a highercognitive process, decision-making, using a more naturalisticGO/NO go task in which rats take 2-4 sniffs of a scented foodtarget before “deciding” whether to reach for it. In the first study,we simultaneously recorded local field potentials and spikes fromthe piriform and motor cortices as rats performed the task, andanalyzed the data with two forms of directed coherence technique(primarily Granger causality). Our main finding was thatfrequency- and time-specific olfactory-to-motor signalingdeveloped as rats learned to discriminate the GO from theNO-GO cues, in response to apparent motor-to-olfactory“queries” about it. In follow-up studies, we have been recordingsimultaneously from the piriform, orbitofrontal, prelimbic andmotor cortices as rats learn and perform this task as well as a moreautomated and controlled version of it, and analyzing the datawith conditional Granger causality methods. We are finding thatthis olfactory-motor signaling occurs at least partly via theprefrontal cortex, further suggesting that the piriform and motorcortices actively participate in the rat’s decision making process.#38 Functional evolution of chemosensory receptorsPositive Selection Shapes the Function of an Odorant Receptorfor Sex-steroid Derived Odors in PrimatesHanyi Zhuang, Mingshan Chien, Hiroaki MatsunamiDuke University Medical Center Durham, NC, USAOdorant receptors are among the fastest evolving genes inanimals. Positive Darwinian selection was implicated in shapingodorant receptor repertoires in different species. However, little isknown about the selection pressure that has shaped the functionsof individual odorant receptors during evolution. We haverecently demonstrated a link between the in vitro function of ahuman odorant receptor, OR7D4, and in vivo olfactoryperception of two steroidal ligands, androstenone andandrostadienone, chemicals that are shown to affect physiologicalresponses in humans. In this study, we analyzed what selectionpressure might affect the function of OR7D4 in primateevolution. Orthologs of OR7D4 and another closely relatedreceptor, OR7D1, were cloned from different primate species.Ancestral reconstruction allowed us to reconstitute additionalputative OR7D4 orthologs in hypothetical ancestral species.Functional analysis of these orthologs showed an extremelydiverse range of OR7D4 function in various primate species.We detected evidence for positive Darwinian selection acting onvarious amino acid residues of OR7D4 throughout primateevolution. Functional analysis of the nonsynonymous changes inthe subset of Great Ape lineage revealed that positively selectedsites caused changes in receptor function. Our results support theidea that positive selection has exerted influences on the dynamicfunctional evolution of OR7D4 in primates.#39 Functional evolution of chemosensory receptorsCopy-number variation map obtained by high-resolutiongenomics reflects human olfactory receptor diversity andevolutionJan Korbel 1 , Yehudit Hasin 2 , Tsviya Olender 2 , Alexander EckehartUrban 3 , Philip Kim 4 , Jason Affourtit 5 , Timothy Harkins 6 , MichaelEgholm 5 , Michael Snyder 3 , Doron Lancet 2 , Mark Gerstein 31EMBL Heidelberg, Germany, 2 Weizmann Institute Rehovot,Israel, 3 Yale University New Haven, CT, USA, 4 University ofToronto Toronto, ON, Canada, 5 454 Life Sciences Branford, CT,USA, 6 Roche Applied Science Indianapolis, IN, USAOur current research combines large-scale experimental andcomputational data-mining approaches for studying the extentand the mutational formation-mechanisms of genomic structuralvariants. Structural variants, frequently referred to as copynumbervariants (CNVs), are >1kb deletions, duplications,insertions, and inversions responsible for most genetic variation inhumans. We recently developed paired-end mapping, an approachinvolving massive sequencing of the end-stretches of 3kb genomicDNA fragments and aligning them against a reference genome toidentify CNVs at high resolution. Applying this approach to twohuman genomes allowed us to obtain insights into the extent atwhich CNVs affect genes. Specifically, we observed a strikingenrichment of CNVs among the olfactory receptor (OR) genefamily, and thus hypothesized that CNVs may play an importantrole in the evolution of the human OR repertoire. To enableinvestigating the impact of CNVs on ORs in a larger populationsample, we designed subkilobase-resolution tiling arrays enablingus to detect CNVs in all genomic OR loci across 25 individuals.We identified 93 OR gene loci and 151 pseudogene loci affectedby CNVs. Specifically, our results show an enrichment of CNVsamong ORs having a close human paralog or such lacking a oneto-oneortholog in chimpanzee. Interestingly, among the latter weobserved an enrichment in CNV losses over gains, a findingpotentially related to the diminution of the human OR repertoire.Extensively mining data from personal genomics projects enabledus to detect, at basepair-resolution, various novel CNVs, some ofwhich likely represent common variants contributing to interindividualdifferences in the human OR gene content.#40 Functional evolution of chemosensory receptorsSequencing the entire OR gene repertoire (and other GPCRs)in a large number of individualsYoav GiladUniversity of Chicago Chicago, IL, USAWe developed a multiplexed protocol to sequence the entirerepertoire of intact OR genes in humans (as well as hundreds ofother GPCRs) using ultra-high throughput sequencingtechnology. We demonstrate that by using multiplex PCRs in one96-well plate, and by sequencing the products in one Solexa laneper individual, we are able to fully sequence an individual’s ORgene repertoire with enough coverage to call heterozygote sites.Our approach can be used to conduct association studies andpopulation genetic analyses using the entire repertoire of ORgenes – while to date, such studies typically focus only on asmall subset of OR genes.16 | AChemS Abstracts 2009

#41 Functional evolution of chemosensory receptorsRapid evolution of two odorant-binding protein genes,Obp57d and Obp57e, in DrosophilaTakashi MatsuoTokyo Metropolitan University Tokyo, JapanOdorant-binding proteins (OBPs) are secreted molecules found ininsect chemosensory organ, where they function together withodorant and taste receptors. Two OBP genes, Obp57d andObp57e, are involved in the evolution of unique host-plantpreference in Drosophila sechellia. D. sechellia exclusivelyreproduces on the ripe fruit of Morinda citrifolia (Tahitian Noni),which contains octanoic acid that is toxic to other Drosophilaspecies. Behavioral analysis of D. melanogaster knockout strainssuggested that Obp57d and Obp57e participate in the tasteperception of octanoic acid. Comparisons of genomic sequencesat the Obp57d/e locus from 27 Drosophila species revealed thatthe OBP gene number at this locus is different between species.Phylogenetic analysis suggested that Obp57d and Obp57e aroseby gene duplication at the early stage of the melanogaster speciesgroup evolution, followed by differentiation of the ORFsequences from each other. While most species in themelanogaster species group maintain both Obp57d and Obp57e,some species have lost either gene. Expression pattern of Obp57dand Obp57e is also different between species. The two OBPs areexpressed only in the gustatory sensilla on the legs in the speciesthat have both Obp57d and Obp57e, whereas the additionalexpression in the gustatory sensilla on the mouthparts wasobserved in the other species. Behavioral analysis of variousspecies revealed that the feeding preference for octanoic acidnegatively correlates with the OBP transcripts level in themouthparts. Gene duplication and the subsequent ORFdifferentiation, as well as changes in the expression pattern, couldbe important evolutionary mechanisms by which OBP genesdevelop their functional diversity, promoting the behavioralevolution among species.#42 Functional evolution of chemosensory receptorsBimodal Function of Drosophila Odorant ReceptorsDieter Wicher, Ronny Schäfer, Marcus C. Stensmyr,Bill S. HanssonMax Planck Institute for Chemical Ecology Jena, GermanyOdorant signals are detected by binding of odor molecules toodorant receptors (ORs) that belong to the G-protein-coupledreceptor (GPCR) family. The receptors couple to G-proteins,most of which stimulate cAMP production. This opens cyclicnucleotide-gated ion channels and depolarises the olfactorysensory neuron. Insect OR proteins lack any sequence similarityto other GPCRs and show an inverted orientation in the plasmamembrane. The ORs are dimers composed of an odor-specificOR protein (e.g., Drosophila Or22a) and a ubiquitously expressedchaperone protein (as Drosophila Or83b). As G-proteins areexpressed in insect OR neurons, and olfactory perception ismodified by mutations affecting the cAMP transduction pathwaythis study was aimed at finding out the function of insect ORs.For this sake we expressed Or22a and Or83b in HEK293 cells andperformed calcium imaging and patch clamp experiments.Application of odorants produced nonselective cation currentsactivated via both an ionotropic and a metabotropic pathway,and a subsequent increase in the intracellular Ca 2+ concentration.Expression of Or83b alone provided functional ion channelsinsensitive to odorants, but directly activated by intracellularcAMP or cGMP. Furthermore, application of only 1 nM cAMPto excised inside-out patches caused a half-maximal currentresponse. However, as current production developed slowly theactivation mechanism is different from the gating known fromionotropic receptors. Insect ORs thus form ligand-gated channelsas well as complexes of odorant sensing units and cyclicnucleotide-activated nonselective cation channels.#43 Making sense of fat tasteMaking Sense of Fat TasteTimothy A. GilbertsonUtah State University Logan, UT, USAThe importance of understanding the sensory cues for dietary fathas been underscored by the recent surge in dietary-inducedobesity. This epidemic of obesity has been attributed to theincreased intake of high fat, high carbohydrate, and caloricallydensediets. While the textural properties of fats have long beenaccepted to be its most salient sensory cue, emerging data from anumber of laboratories has begun to point to their being a “tasteof fat” as well. This symposium will provide a multidisciplinaryoverview of the evidence that supports the idea that the gustatorysystem is capable of responding to the chemical cues contained indietary fat and will look at the ability of free fatty acids to actboth as a taste primer and taste modulator. The implications of thepresence of a fat detection system will be discussed. Discussants:J.-P. Montmayeur; R. Contreras.#44 Making sense of fat tasteLigand specificities to putative fat receptor candidatesCD36 and GPR120 and licking behavior correspondingto the ligands in miceShigenobu Matsumura, Takeshi Yoneda, Ai Eguchi, YasukoManabe, Satoshi Tsuzuki, Kazuo Inoue, Tohru FushikiGraduate School of Agriculture, Kyoto University Kyoto, JapanFatty foods are palatable to animals including humans.Several studies have indicated that animals recognize thepresence of fat in foods not only by the texture of the food butalso chemically in the mouth: this suggests that the chemicalperception of fat is involved in the acquisition of a strong avidityfor fat. CD36 is known as a fatty acid transporter in the muscle oradipose tissue. Previously we have reported that CD36 isexpressed in the taste bud cells of the posterior tongue. CD36-deficient mice showed lower avidity for long-chain fatty acidenrichedsolutions. In addition to CD36, we have found thatGPR120, a G-protein coupled receptor that functions as a specificunsaturated long-chain fatty acid receptor in the gastrointestinaltract, is expressed in the taste bud cells of anterior and posteriortongue. A wide variety of molecules are known to be a ligand forCD36, including saturated or unsaturated fatty acid, somelipoproteins, cholesterol, thrombospondin and so on. However,HEK293 cells overexpressing GPR120 revealed that only longchainunsaturated fatty acids are potent ligand for GPR120. Inaddition, the palatability of fatty acids for mice assessed by theshort term licking behavior is very similar to the ligand specificityfor GPR120. These results raise the possibility that GPR120Abstracts | 17

expressed in the taste cells may also be involved in the chemicalreception and palatability of dietary fat. CD36 and GPR120,however, are different in the location of expression, ligandspecificity and possibly, intracellular signaling pathway.These facts indicate that these two fatty acid receptorsexpressed in the tongue may construct independent pathwaysfor the sensing of fat.#45 Making sense of fat tasteFatty Acid Transduction in Chemosensory CellsTian Yu, Bhavik P. Shah, Pin Liu, Timothy A. GilbertsonUtah State University Logan, UT, USAGiven the dramatic rise in obesity that appears to be correlatedwith an increase in dietary fat intake, there has been increasinginterest in understanding the cellular and molecular mechanismsthe body uses to recognize dietary fatty acids (FA). We havefocused on three fat responsive cell types in our attempt tounderstand these mechanisms. Preingestively, we have attemptedto elucidate mechanisms underlying the taste and texture of fat byusing molecular and cell-based assays on taste receptor cells(TRCs) and trigeminal neurons (TGNs), respectively. In the gut,we have explored these pathways in the enteroendocrine cells(EECs) of the small intestine. Molecular data have shown that allthree cell types express a variety of putative FA receptors,including CD36, FA-activated GPCRs and FA-sensitive DRKchannels. Cell-based assays (patch clamp recording; calciumimaging) combined with pharmacological and molecular(RNA interference) approaches have been used by our laboratoryto unravel the FA transduction pathway(s) within thesechemosensory cells. While differences exist in the transductionpathways in these cell types, commonalities include a dependenceupon G protein activation, a role for the phospholipase C,activation of TRP-like channels, and a role for voltage-activatedcalcium channels in the FA signaling pathway. We will discuss ourcurrent data and present a model for the transduction of fattyacids in chemosensory cells.#46 Making sense of fat tasteOral Detection of Fatty Acids by RatsDavid W. PittmanDepartment of Psychology, Wofford College Spartanburg,SC, USAEvidence is accumulating to support a role for the gustatorysystem in providing an immediate sensory signal allowingdetection of the fatty acid components of dietary fat duringconsumption by rats. Early research showed innate preferencesfor dietary fat in humans and rats. Putative fatty acid receptorshave been identified in rat taste receptor cells. Consistent with theaction of fatty acids on taste receptor cells, we have shown thatfatty acids increase licking to appetitive tastants during briefaccessbehavioral assays, while licking to aversive stimulidecreased in a manner reflective of an increase in the perceivedintensity of the tastants. Conditioned taste aversion studies in ourlaboratory have demonstrated fatty acid detection thresholds atphysiologically-relevant concentrations (2.5-66 M) which aremuch lower than fatty acid concentrations likely produced bylingual lipase during dietary fat consumption. Additionally, wehave demonstrated genetic influences on the sensitivity of fattyacid detection between male / female rats and obesity-prone / –resistant strains of rat as well as an environmental influence ofa high-fat diet on the sensitivity of fatty acid detection. New datasuggests that olfactory cues are most likely not sufficient to allowdetection and avoidance of fatty acids following a conditionedtaste aversion and that orosensory signals generated by fatty acidsare likely unique from sensations associated with the prototypicaltastes of sweet, sour, salty, and bitter chemicals. Finally, the mostcompelling evidence of the gustatory detection of fatty acids byrats arises from studies in which gustatory nerve transectionsand genetic knockouts of specific fatty acid receptors in thegustatory system produce impairments in the behavioraldetection of fatty acids.#47 Making sense of fat tasteOral Detection of Free Fatty Acids in HumansRichard D MattesPurdue University W. Lafayette, IN, USAThere is increasing recognition that free fatty acids (FFA) areimportant signaling molecules. Increasing evidence suggests theymay play such a role in the oral cavity of humans. Psychophysicalstudies that attempt to control non-gustatory cues (e.g., visual,odor, irritancy, tactile) indicate humans can detect FFA varyingin chain length (C:6 – C:18) and saturation (saturated, monounsaturated,poly-unsaturated). Spatial testing reveals that FFA(C:6 to C:18) can be detected on the dorsal, anterior; lateralposterior, and posterior tongue. All stimuli could be assignedgraded intensity ratings from each site. Given the ligandspecificity of currently identified putative FFA receptors,the data indicate that humans either have multiple transductionmechanisms in the different tongue regions and/or that there is anon-specific mechanism (e.g., diffusion) responsible. Non-normalthreshold distributions are suggestive of a genetic basis for fatdetection. Oral exposure to FFA also elicits a biphasic rise inplasma triacylglycerol (TG). Recent findings indicate there is anon-specific component to this response, but that it is mostrobust to oral exposure to dietary fat. It occurs after a single 10second exposure, but the second phase shows greater qualityspecificity with longer stimulus exposures (e.g., 20minutes). About half of the TG in the acute peak is derived fromlipid consumed at the prior eating event indicating there issubstantial lipid storage in the GI tract, presumably in jejunalenterocytes. While TG is likely tasteless, the other sensoryproperties it contributes to foods are generally viewed aspositive. In contrast, FFA are aversive, so may serve as a warningto avoid foods with high levels. The full range of implications offat detection remains to be characterized.18 | AChemS Abstracts 2009

#48 Workshop: Computational problemsin sequential stages of odor processingExploring the Interaction between Odorants and OdorantReceptors using Functional and Computational MethodsCharles W. Luetje, Sarah E. Repicky, Tatjana AbaffyMolecular and Cellular Pharmacology, University of MiamiMiami, FL, USAThe mammalian olfactory system uses a vast array of odorantreceptors to detect and distinguish among an enormous numberof odorant molecules. However, odorant ligand specificity hasbeen determined for only a handful of odorant receptors and inonly a few cases have the details of ligand recognition beenexamined at the molecular level. Expanding our knowledge of themolecular basis for ligand recognition among odorant receptors ischallenging task. We are using functional analysis and site-directedmutagenesis, in combination with computational homologymodeling and virtual ligand docking, to examine the interactionbetween odorant ligands and mammalian odorant receptors. Wehave developed a functional assay for ORs using the Xenopusoocyte expression system and robotic electrophysiology. Thisassay allows us to use both conventional mutagenesis and theSubstituted Cysteine Accessibility Method to test and refine ourinitial receptor models. The assay also allows functional testing ofligand predictions derived from virtual docking. By iteratingbetween computational and functional approaches, we hope toimprove our understanding of the interaction between odorantsand odorant receptors, with a particular emphasis onunderstanding ligand selectivity.#49 Workshop: Computational problems insequential stages of odor processingModeling Diversity in the Signal Transduction of theMouse Olfactory Receptor NeuronDaniel P. DoughertyMichigan State University, Lyman Briggs College of Science andDept. of Statistics and Probability East Lansing, MI, USAWe use various statistical parameterization techniques to drive thedevelopment of a physiologically-based computational model ofthe slow (transduction) and fast (action potential) currents of theolfactory receptor neuron in mouse. The response to an odorantplume can elicit a diversity of responses across a population ofORN. We hope that by bridging various statistical andcomputational approaches an improved understanding of themolecular basis of this diversity can be obtained.#50 Workshop: Computational problems insequential stages of odor processingOdorant mixture interactions in rat olfactory receptorneurons: models and experimentsJean-Pierre Rospars 1 , Petr Lansky 2 , Michel Chaput 3 , PatriciaDuchamp-Viret 31UMR 1272 Physiologie de l’Insecte, INRA, Versailles, France ,2Institute of Physiology, Academy of Sciences, Prague, CzechRepublic , 3 UMR 5020 Neurosciences Sensorielles, Comportement,Cognition, Lyon, FranceAn odor perception is the brain’s translation of the activation byodorant molecules of olfactory receptor neurons (ORNs) locatedin the nasal cavity. Most ORNs express a single type of olfactoryreceptor that is differentially sensitive to a wide variety of odorantmolecules. Many kinds of odorant-receptor interactions can takeplace, especially with mixtures of many odorants which make upthe vast majority of real world odors. The simplest kind ofinteraction is pure competition when two or more agonists canbind to the receptor site which triggers receptor activation,although only one can be bound at a time. Noncompetitive effectsmay result from various mechanisms, as for example agonistbinding to another site of the receptor (allostery). Then twomolecules can bind at the same time and binding at the second sitemay modify the properties of the main binding site. We developeda quantitative model based on odorant-receptor interaction,relating the stimulus concentration to the ORN firing frequency.We extended this model to predict the ORN response in thesimple case of pure competitive interaction between odorants.To test the model we recorded the electrophysiological responsesof rat ORNs in vivo to odorant agonists and their binary mixturesat various concentrations. We interpreted the resultingconcentration-response curves in the framework of our model.We found that it accounts for all curves obtained with singleodorants and for about half of those obtained with binarymixtures. In the other half, the experimental curves weresignificantly different from those predicted by the model,indicating the occurrence of noncompetitive interactions.These noncompetitive interactions raise challenging problemsfor predicting the perception elicited by most odors, which likeperfumes, wine bouquet, food aroma, etc. are mixtures of dozens,even hundreds, of odorants because they imply that the brain’scode for mixtures of odorants will not be easily predicted fromthe known codes of their individual components.#51 Workshop: Computational problems insequential stages of odor processingOdor Maps in the Mouse Olfactory BulbVenkatesh N Murthy 1 , Dinu F Albeanu 2 , Edward R Soucy 1 ,Markus Meister 11Harvard University Cambridge, MA, USA, 2 Cold Spring HarborLaboratory Cold Spring Harbor, NY, USAMice and rats use ~1,000 olfactory receptor types to probechemical space. Each glomerulus in the olfactory bulb receivesinput from a single receptor type, whose ligand binding propertiesdetermine the spectrum of odor responses. In this way, the layoutof glomeruli on the bulb forms a two-dimensional map of odors.We recorded the odor responses of dorsal glomeruli in miceexpressing synaptopHluorin in sensory nerve terminals. By usinga chemically-diverse battery of several hundred odors, we couldassign unique functional identities to several dozen glomeruli.This allowed us to determine that the position of a givenAbstracts | 19

glomerulus varies across individuals by only 1 glomerular spacing,corresponding to a precision of 1 part in 1000. We also askedwhether the layout of glomeruli is systematically related to theirodor sensitivities. The odor response spectra of two neighboringglomeruli were as dissimilar as those of distant glomeruli. Thislocal diversity of odor responses will have importantconsequences for how mitral cells sample odor space. We havebegun to examine this next stage of processing in the bulb byimaging postsynaptic signals in the dendrites of mitral cells inmice expressing the calcium indicator GCaMP2 and multiphotonmicroscopy. Initial results indicate that the population responsesof mitral cell apical tufts are similar to the presynaptic mapsconstructed from synaptopHluorin mice. We were also able torecord robust odor-evoked responses from a large population ofindividual lateral dendrites, and are currently analyzing theirodor tuning.#52 Workshop: Computational problems insequential stages of odor processingDistributed Lateral Inhibition in the Olfactory Bulb:Anatomical Evidence and Functional Implications ofLong-range Interactions of Mitral and Tufted CellsMatthew E Phillips, Hetal K Patel, David H Kim, Gordon MShepherd, David C WillhiteYale University New Haven, CT, USADetecting environmental chemical information is thought tobe a high dimensional sensory task. In mammalian olfaction,a complex system involving many proteins targets axons ofsensory neurons expressing the same receptor to specificglomeruli organized in roughly a two dimensional sheet.Adjacent glomeruli in this sheet, however, may or may not detectsimilar odor information. Decorrelation of input through lateralinhibition therefore may need to act over longer distances andmore selectively than a simple center-surround as found in theretina. Recent anatomical and physiological data suggest thatlateral interactions between mitral and tufted cells mediated bygranule cells are sparse and act over relatively long distances.I discuss new evidence of the distribution of synapses on thelateral dendrites, and hypothesize that function of selective lateralinteraction is signal decorrelation.do not reflect special properties of odorant receptors. Multiplenegative feedback circuits normalize odor-evoked activityand facilitate the concentration-independent recognition ofodors. Decorrelation (contrast enhancement) among physicallysimilar odorants arises from location-independent synapticmechanisms within the glomerular layer and can be dynamicallyregulated by descending neuromodulatory projections. Analogousdecorrelation processes proposed to operate in the externalplexiform layer are better-suited to learning functionaldecorrelations based upon experience. In contrast to thetemporally unsophisticated spike trains of olfactory sensoryneurons, the secondary olfactory representations mediated bymitral cells are sparser and suggest a dynamical, spike timingsensitiveprecedence code. These principles underlie a theory ofolfactory generalization that governs the perception of similarityamong related odorants, including the plasticity of this perceptionand the observation that experimental omission of components ofcomplex odors can have negligible effects on the results ofolfactory perceptual tasks.#54 Follow the head, not only the nose:Top-down influences on olfactory perceptionThe Nose is Just the Beginning: Patterns, Objects andExperience in OlfactionDonald A. Wilson 1,21Nathan Kline Institute Orangeburg, NY, USA,2NYU School of Medicine New York, NY, USAPatterns of sensory receptor neuron activity place constraints onultimate perceptions, but do not necessarily allow prediction ofthe perception. Perception derives from computations performedby central circuits, which combine sensory afferent input withpast experience, expectation, context and internal state. In thisregard, olfaction is no different from other sensory systems. I willbriefly argue that primary olfactory cortex is an associativenetwork, merging complex spatiotemporal patterns of olfactoryreceptor input with descending information about pastexperience, expectation, context and internal state. In doing so,multi-modal and emotion-laden memories of odor objects arebuilt, shaping subsequent olfactory perception.#53 Workshop: Computational problems insequential stages of odor processingA two-stage model of odor representation and processingin the olfactory bulbThomas A. ClelandDept. Psychology, Cornell University Ithaca, NY, USAMuch is known about the neurobiology and psychophysics ofolfaction, but this knowledge often lacks a common theoreticalfooting by which it can be integrated into a single framework ofodor representation and processing. I here present a generaltheory of olfactory bulb operations, with emphasis on thearchitectural and functional differences between the two discretelayers of intrabulbar computation: the glomerular layer and theexternal plexiform layer. The olfactory system’s high sensitivityand broad dose-response functions are consequences ofestablished pharmacological and physiological mechanisms and#55 Follow the head, not only the nose:Top-down influences on olfactory perceptionLearning to smell: Olfactory perceptual learning and itsecological impactWen LiUniversity of Wisconsin-Madison, Department of PsychologyMadison, WI, USAIncreasing evidence suggests that human olfaction is not dictatedby the odorant chemical structure, but rather, reflects higherordercognitive influences. In this talk, I will discuss recent workdemonstrating that human odor quality coding alters andolfactory discrimination improves with experiences from mereodor exposure to olfactory aversive learning. Collected usingpsychophysics, autonomic physiology and functional magneticresonance imaging, these data will indicate that 1) simple odorexposure enhances perceptual and neural discrimination ofwithin-category odors such that, for instance, following passive20 | AChemS Abstracts 2009

several brain regions. This symposium will focus on recent studiesthat have shown the influence of GABA on virtually all aspects ofolfactory bulb interneuron development, from proliferation andmigration of progenitors, to maturation and functionalsynaptogenesis resulting in integration and phenotypicdifferentiation. Specifically, Angelique Bordey will speak aboutthe interplay between glutamate and GABA on the rate of bothgeneration and migration of olfactory bulb interneuronprogenitors. Adam Puche will address issues related to expressionof the GABAergic phenotype during migration of theseinterneuron progenitors. John Cave will present data suggestingthat GABA modulates differentiation of GABA/dopamineexpressingperiglomerular cells. Pierre-Marie Lledo will discusshow centrifugal innervation of olfactory bulb interneuronprogenitors modulates their differentiation. David Willhite willdescribe GABA-related electrophysiological and projectionparameters of olfactory bulb granule cells in relationship to odorprocessing. The work presented in this symposium highlights thecontinually expanding knowledge of the pleiotropic functionsperformed by GABA in the nervous system.#60 GABA in the developing olfactory system:From generation to differentiationGABA differentially modulations migration of SVZprogenitor subpopulationsAdam C PucheUniversity of Maryland Baltimore, MD, USAOlfactory bulb interneurons are continuously generatedthroughout development and in adult. These neurons are born inthe subventricular zone (SVZ) and migrate along the rostralmigratory stream (RMS) into the olfactory bulb (OB) where themajority become local GABAergic interneurons. While thepostnatal SVZ is best known as a source of OB interneurons, italso gives rise to other interneuron populations. We havepreviously shown neurons also migrate ventrally from thepostnatal SVZ to form the islands of Calleja and contributeneurons to the olfactory tubercle. Since neuronal migration fromthe ganglionic eminence to cortex, and from the SVZ to the OB,can be modulated by neurotransmitters we hypothesized thatSVZ derived ventral migration would also be modulated byneurotransmitters. GABA is a potent cue reducing the migratoryrate of rostral directed SVZ progenitors. However, unlike rostralmigrating progenitors, those heading ventral respond to GABAwith enhanced migration. In addition to altering migration rate,progenitor cells migrate toward a point source of GABAsuggesting GABA acts as a guidance factor. Indeed, disruption ofGABA signaling in vitro disrupts interneuron organization in thebasal forebrain. These data suggest that GABA can modulatesboth rostral and ventral SVZ progenitor migration, butsubpopulations respond differentially, and may be an importantcue for organizing ventral forebrain interneurons.#61 GABA in the developing olfactory system:From generation to differentiationGABA and glutamate interplay on subventricular zone cellproductionAngelique BordeyYale Univ Sch Med New Haven, CT, USAThe production of adult-born neuron is an ongoing processaccounting 10,000 to 30,000 immature neurons every day.This high turnover rate necessitates profound control mechanismsconverging onto neural stem cells and neuroblasts. Thesemechanisms provide a balance between proliferation, migrationand survival of stem cells and their daughter cells in theneurogenic microenvironment to achieve adequate adult bornneuron production. We will elaborate on a novel epigeneticcontrol of adult neurogenesis via highly coordinated nonsynapticcell-cell signaling. This communication is based onneurotransmitters, whose extracellular concentration dependson cell number. In the adult subventricular zone, glial fibrillaryacidic protein (GFAP)-expressing progenitors (called GFAPprogenitors)generate neuroblasts migrating to the olfactory bulb.Recent findings from our lab show that neuroblasts release theneurotransmitter GABA providing a negative feedback control oftheir own migration and stem cell proliferation through unknownintracellular pathways. Neuroblasts display coordinated calciumactivity that is expected to lead to calcium-dependent GABArelease. Upon stimulation by GABA, stem cells are depolarizedand release glutamate via a vesicular process. Glutamate thenactivates Glu K5 kainate receptors and NMDA receptorscontrolling neuroblast migration and survival, respectively.The timing of neurotransmitter release and their spatial diffusionwill determine the convergent co-activation of neuroblasts andstem cells, and scale their development.#62 GABA in the developing olfactory system:From generation to differentiationGABA-enhanced differentiation of the olfactory bulbdopaminergic phenotypeJohn W Cave 1,2 , Yosuke Akiba 2 , Harriet Baker 1,21Weill Cornell Medical College New York, NY, USA, 2 BurkeMedical Research Institute White Plains, NY, USAGABA regulates the proliferation and migration rates as well asdendritic elongation and stabilization of olfactory bulb (OB)interneuron progenitors. Given these developmental roles, aninteresting, but largely unexplored, question is whether GABAcan also modulate differentiation of specific interneuronphenotypes. To determine whether GABA modulates activitydependentexpression of tyrosine hydroxylase (TH), a marker ofOB dopaminergic neurons differentiation, neonatal forebrain slicecultures were prepared from transgenic mice expressing GFPunder the control of the 9kb TH upstream gene regulatory region.These studies revealed that the induction of TH/GFP expressionunder depolarizing conditions (25mM KCl) is completelyinhibited by nifedipine, an L-type Ca+2 channel blocker, andpartially inhibited by ¥-agatoxin, a P/Q Ca+2 channel blocker.This combined action of both L and P/Q-type Ca+2 channels issimilar to the established mechanism for synaptic release ofGABA from periglomerular interneurons. Our studies alsorevealed that exogenous application of GABA further increased22 | AChemS Abstracts 2009

TH/GFP expression levels in depolarized slice cultures. ThisGABA-mediated increase of TH/GFP expression was blocked byinhibitors of either GABA-A or GABA-B receptors as well asinhibitors of metabotropic and ionotropic glutamate receptors.Although GABA is sufficient to both depolarize OB interneuronprogenitors and activate L-type Ca+2 channels, GABA, by itself,was not sufficient to induce TH/GFP expression in our studies.Instead, the data indicate that induction of TH/GFP expressionspecifically required glutamate-mediated depolarization andactivation of L-type Ca+2 channels, and that differentiation of theOB dopaminergic phenotype is coupled to its co-expressedGABAergic phenotype.#63 GABA in the developing olfactory system:From generation to differentiationDynamic development of synaptic inputs on maturinginterneurons in the adult OBPierre-Marie Lledo, Antoine Nissant, Cedric Bardy,Hiro Katagiri, Kerren Murray, Institut Pasteur Paris, FranceIn addition to relaying sensory information from the primarysensory epithelium to the cortex, the olfactory bulb (OB)receives massive inputs from several centers. Prime among thecentrifugal inputs are the dense innervation that preferentiallytargets granule cells (GC) of the OB. Since newborn inhibitoryneurons, including GC, continuously migrate into the OBthroughout life, it is still uncertain whether their first synapticcontact originates from ascending (i.e., sensory inputs) ordescending (i.e., centrifugal fibers) pathways. The present studydemonstrates that glutamatergic centers, extrinsic from the OBcircuit, contact the newcomers on their proximal section of theapical dendrite, much before receiving synaptic inputs fromintrinsic OB circuit. This finding indicates that before feedforwardsensory inputs target the distal portion of the new GCdendrite, the animal’s behavioral state may shape integration ofnew OB neurons by establishing early synaptic contacts. Toexplore the functional consequences of these early glutamatergicsynaptic contacts, we investigated plasticity at glutamatergicsynapses onto the newly-generated GC. We find that, shortlyafter their arrival in the bulb, a subset of excitatory synapsesexhibits long-term potentiation. This property fades withmaturation of the new neurons, and disappears in mature GC.These results demonstrate that recently-generated adult-bornOB interneurons undergo different experience-dependentsynaptic modifications compared with their pre-existing matureneighbors, and provide a possible substrate for adultneurogenesis-dependent olfactory learning. Understanding howcentrifugal inputs develop on adult-generated GC is therefore acritical step necessary to decipher the unexpected impact ofbehavioral states on adult neurogenesis.#64 GABA in the developing olfactory system:From generation to differentiationTranssynaptic Tracing Studies Suggest CombinatorialGating of Olfactory Information is Mediated byGABAergic Interneurons in the Granule Cell LayerDavid H Kim 1 , Andrew Y Chang 1 , Matthew E Phillips 1 , AureliePala 1 , Hetal K Patel 1 , Janna C Nawroth 2 , Katherine T Nguyen 1 ,Michele Migliore 1,3 , Gordon M Shepherd 1 , David C Willhite 11Yale University New Haven, CT, USA, 2 California Institute ofTechnology Pasadena, CA, USA, 3 National Research Council,Institute of Biophysics Palermo, ItalySubsets of newly-generated GABAergic interneurons integrateinto a complex network of synaptic connections in the granule celllayer of the olfactory bulb. Viral transsynaptic tracing studieshave shown that there is a tendency toward a columnarrelationship of granule cells with M/T cells. We interpreted thecolumns to arise from clusters of granule cell synapses along thelateral dendrites of M/T cells. Therefore, dual injections of tracingstrains expressing either red or green fluorescent proteins atdifferent sites in the medial glomerular layer was expected toproduce red, green and yellow granule cell columns. However, thegranule cell columns that are connected to both red and greenM/T cells tend to show red and green non-colocalization(segregation) rather than yellow colocalization (convergence)within the same spatial columnar unit. This shows that the M/Tlateral dendrites from widely separated glomeruli that overlap at aspecific location in the EPL are generally connected to differentgranule cells, rather than the same population. These resultssuggest that further subdivisions of granule cells within acolumnar unit may serve specific functions. To form hypothesesof how this network architecture influences odor informationprocessing, computational models incorporating assumptions ofsegregated or convergent granule to mitral cell connectivity werecreated. Results indicate that segregated connections are sufficientunder the tested conditions to allow granule cells to modulateM/T cell firing using information from multiple lateral sources,while convergent connections place constraints on lateralinfluence. I hypothesize that sparse, segregated connectivityallows combinatorial logic gating, a function that is one of theroles of GABAergic interneurons in the olfactory circuit.#65 Olfactory and Vomeronasal SystemsRepertoire of chemosensory receptors from the genomeof the jawless vertebrate Petromyzon marinusScot V. Libants 1 , Kevin Carr 2 , John H. Teeter 3 ,Yu-wen Chung-Davidson 1 , Curt Wilkerson 2 , Weiming Li 11Department of Fisheries and Wildlife, Michigan State UniversityEast Lansing, MI, USA, 2 Research Technology Support Facility,Michigan State University East Lansing, MI, USA, 3 The MonellChemical Sense Center Philadelphia, PA, USAIn gnathostomes, chemosensory receptors (CR) expressed inolfactory epithelia are encoded by evolutionarily dynamic genefamilies encoding odorant receptors (OR), trace amine-associatedreceptors (TAAR), and two types of vomeronasal receptors (V1Rand V2R). Whether these gene families arose in basal or advancedvertebrates has not been resolved because these families have notbeen examined systematically in agnathan genomes. The sealamprey Petromyzon marinus is the only extant jawless vertebratewhose genome has been sequenced, and has been shown to detectAbstracts | 23

fewer amino acids and steroids than teleosts. We have identifieda repertoire of 59 intact single-exon CR genes, including 27 OR,28 TAAR, and four V1R-like genes. Expression among these CRfamilies was detected in the olfactory organs of parasitic- andreproductive-stage adults using Roche 454 GS20 sequencing.We failed to identify orthologs or pseudogenes of the multi-exonV2R family that has expanded in teleost genomes, but did identifytwo intact calcium-sensing receptors (CASR) and severalmetabotropic glutamate receptors (MGR). We conclude that OR,TAAR and V1R arose in chordates after the cephalochordateurochordatesplit, but before the diversification of jawed andjawless vertebrates. The advent and diversification of V2R genesfrom glutamate receptor-family G protein-coupled receptors,most likely the CASR, appears to have occurred after thedivergence of jawed and jawless vertebrates.#66 Olfactory and Vomeronasal SystemsEmx2 Stimulates Odorant Receptor Gene Expression andControls OSN Axon GrowthJeremy C. McIntyre, Soma C. Bose, Timothy S. McClintockDepartment of Physiology, University of Kentucky Lexington,KY, USAThe expression of a single odorant receptor (OR) gene byeach olfactory sensory neuron (OSN) is critical for odordiscrimination, yet the mechanism of OR gene choice is largelyunknown. Putative OR promoters contain homeodomain-likesites, implicating homeobox transcription factors, like Emx2,in OR gene expression. We investigated whether OR geneexpression was altered in Emx2 -/- mice. The olfactory epitheliumof Emx2 -/- mice at embryonic day 18.5 had normalpseudostratification and was morphologically normal exceptfor a decrease in thickness due to a 42% reduction in OMP +mature OSNs. This effect was minor compared to changes in ORgene expression. 50% – 80% of Class I and Class II OR mRNAswere disproportionately reduced in abundance compared to thesmall decreases observed for mature OSN-specific mRNAs. Theintensity of in situ hybridization was normal for these ORs, butfewer OSNs expressed them (many fewer than the reduction inmature OSNs). A few Class II ORs (

not activation and sensitivity. Furthermore, altered adenylatecyclase III (ACIII) signaling may underlie the immature OMP-KO phenotype, as blocking ACIII phosphorylation in P30 wtcells mimics the KO phenotype. We conclude that OMP is criticalfor functional maturation of OSNs.#69 Olfactory and Vomeronasal SystemsSensory Adaptation in the Vomeronasal OrganFrank Zufall 1 , Silke Hagendorf 2 , Jan Weiss 1 , Marc Spehr 2 ,Trese Leinders-Zufall 1 , Jennifer Spehr 21Dept. Physiology, University of Saarland, School of MedicineHomburg, Germany, 2 Dept. Cellular Physiology,Ruhr-University of Bochum Bochum, GermanyThe mammalian vomeronasal organ (VNO) mediates theregulation of social behaviors by complex chemical signals.These cues trigger transient elevations of intracellular Ca 2+ invomeronasal sensory neurons (VSNs), but the functional role ofsuch Ca 2+ elevations is unknown. We show (1) that VSNs undergosensory adaptation; (2) that VSN adaptation depends on negativefeedback signaling by Ca 2+ which enters the cell throughtransduction channels but not voltage-activated Ca 2+ channels;(3) that adaptation is required for sensitivity modulation ofstimulus-evoked VSN responses and alters the informationtransmitted to the brain; (4) that activated CaM is required forthese effects; (5) that pheromone-sensitive TRPC2-dependentcation channels are inhibited by Ca 2+ -CaM and thus provide asubstantial target for a Ca 2+ -CaM-mediated negative feedbackloop; and (6) that mouse VSN dendritic knobs express Ca 2+ -activated cation channels that could be part of an additional,positive feedback mechanism. These findings identify Ca 2+ -CaMas a previously unrecognized negative feedback signal that tightlyadjusts gain and amplification of the chemotransduction processin VSNs. Future studies should aim at understanding how theinteraction of negative and positive feedback loops in VSN signaltransduction shapes the processing of pheromonal information inthe vomeronasal system.#70 Olfactory and Vomeronasal SystemsFirst Order Blend Processing in the Moth Antennal LobeLinda S. Kuebler, Shannon B. Olsson, Bill S. HanssonDepartment of Evolutionary Neuroethology, Max Planck InstituteFor Chemical Ecology Jena, Germanymoth, Manduca sexta. Using a novel multicomponent stimulussystem and intracellular recording, we analyze the finerepresentation of blends vs. single components in individualantennal lobe neurons responding to combinations of up to sevenhost volatiles. We examined different temporal characteristics(e.g. spike frequency, interstimulus interval, latency) and amongthose a variety of blend interactions were observed, includingsynergism and suppression. Moreover, we found that a singlemorphological type of neuron can exhibit diverse blendinteractions as well as inhibitory and excitatory responsecharacteristics.#71 Olfactory and Vomeronasal SystemsTranslation of Olfactory Input into Behavioral Outputin the Drosophila LarvaShelby A. Montague 1,2 , Dennis Mathew 2 , John R. Carlson 21Department of Cellular and Molecular Physiology, YaleUniversity New Haven, CT, USA, 2 Department of Molecular,Cellular, and Developmental Biology, Yale UniversityNew Haven, CT, USAWe have investigated principles of odor coding by testing theresponses of the Drosophila larval olfactory receptors to a panel ofchemically similar odorants. The anatomy of the larval olfactorysystem is similar to that of the adult while being numericallysimpler. It contains 21 olfactory receptor neurons that project to21 glomeruli in the larval antennal lobe. Of 60 odor receptorgenes, 21 encode functional larval receptors in our laboratorystrain. Using an in vivo expression system, the “empty neuron”system, we tested the responses of the larval receptor repertoire toa panel of 24 pyrazines. Six receptors showed strong excitatoryresponses to one or more pyrazines. Two of these six receptors,Or33b and Or59a, exhibited some excitatory responses thatshowed surprising temporal dynamics; they took up to 15 minutesto return to the baseline firing rate. By contrast, most strongexcitatory responses returned to baseline in less than 3 seconds.We have named these extremely long responses “supersustained”responses. Pyrazines elicited a range of behavioral responses fromstrong attraction to little, if any, attraction when tested using atwo-choice assay. Surprisingly, two pyrazines that haveremarkably similar receptor response profiles, 2-ethylpyrazineand 2-methylpyrazine, elicited dramatically different behavioralresponses. We are currently investigating mechanisms that mayunderlie this difference in behavioral response.Animals typically perceive their olfactory environment as acomplex mixture of many different compounds. Despite this fact,most studies concerning odor detection and coding in insectshave only included single components. In insects, the initialrepresentation of odors occurs in the first olfactory neuropil, theantennal lobe (AL), where three classes of neurons form synapses:olfactory receptor neurons (ORNs), projection neurons (PNs)and local interneurons (LNs). The resultant neural representationof odor mixtures in the AL may be simply a linear summation ofblend components or a non-linear interaction due to odorinformation processing in the AL. The modified representation inthe assembly code is carried by PNs to higher order brain centers.Our goal is to reveal mechanisms of host odor informationprocessing at different levels in the AL (PNs, LNs) of the hawkAbstracts | 25

#72 Olfactory and Vomeronasal SystemsEvidence for a chemosignal in human tearsShani Gelstein 1 , Liron Rozenkranz 1 , Yaara Yeshurun 1 ,Yehuda Roth 2 , Noam Sobel 11Weizmann Institute of Sceience Rehovot, Israel,2ENT Wolfson Medical Center Holon, IsraelEmotional tearing is a uniquely human behavior who’sevolutionary origin and present-day function remain unclear.We hypothesized that emotional tears may act as a chemosignal.Emotional tears were obtained from a female “donor” whoviewed sad films in isolation. In a within-subjects repeated-studydesign, 42 healthy male subjects (age 19-40) smelled (10 sniffs)either fresh tears or saline, counter-balanced for order, and thenwatched two video clips, one emotionally neutral and one sad.We measured mood (17-qestion Ekman questionnaire),psychophysiology (skin conductance, electrocardiogram, earpulse, finger pulse, abdominal respiration, thoracic respiration,skin temperature, and body movement), and endocrine state(salivary testosterone). Within compound analysis revealed that inthe presence of TEARS the emotional movie decreased positivemood (F(1,41)= 8.53, p

POSTER PRESENTATIONS#P1 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsTaste disturbances after tonsillectomy – results of aprospective studyClemens Heiser, Sabine Frey, Karl Hörmann, Boris StuckDepartment of Otorhinolaryngology, Head and Neck Surgery,University Hospital Mannheim Mannheim, GermanyIntroduction: Persistent taste disturbance is a rare complicationafter tonsillectomy. Postoperative dysgeusia has been described incase reports; the number of prospective trials however is limited.The aim of the study was to investigate the frequency, the timecourse, the extent of subjective postoperative taste disorders aftertonsillectomy in adults in a prospective clinical trial. M&M: Since2007, adult patients undergoing tonsillectomy were asked to takepart in the trial. At present, 102 patients (32±12 years, 54% w,46% m) were included. At the day prior to surgery as well as 2weeks, 6 months after tonsillectomy a standardized questionnairewas completed by the patients. The questionnaire addressed a selfassessment of the ability to taste (visual analogue scale) andpotential taste disorders in terms of their quantity, quality, onset,and persistence. Results: To date the results of 2 weeksquestionnaire are available from 71 patients, the 6 monthsquestionnaire from 31. 23 patients (32%) reported taste disordersafter tonsillectomy 2 weeks (postop.). 13 (18%) described a tastedisorder lasting longer than 2 weeks. 5 (16%) experienced tastedisorders that were still present at the 6 month follow up (bittertaste). The subjective assessment of the ability to taste wassignificantly reduced 2 weeks (postop.) (VAS:7,8±1,6to5,7±2,2).Discussion: Subjective taste disorders after tonsillectomy seem tobe more frequent than expected, consisting of subjective hypoandparageusia. A considerable number of patients experiencesubjective taste disorders lasting for more than 6 months. A bittertaste was most frequently reported and the overall sense of tasteseems to be reduced. The trial will continue to gain a longerfollow up and a higher number of patients to verify these results#P2 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsLong-term olfactory outcome in patients with mildtraumatic brain injuries (mTBI)Faye Pesenti, Alain Ptito, Jelena DjordjevicMontreal Neurology Institute, McGill University Montreal, QC,CanadaThe incidence of olfactory deficits in patients with TBI has beenrelated to injury severity suggesting that they are uncommon inmild traumatic brain injury (mTBI). Consequently, there are nostudies that have examined the long-term effect of mTBI onolfactory function. We examined olfactory function in a group ofpatients who sustained a concussion at least one year prior totesting and who complained of persistent post-concussionsymptoms (headaches, dizziness, nausea, fatigue, irritability).Their performance was compared to that of an age- and gendermatchedhealthy control group. None of the subjects withmTBI exhibited olfactory deficits when tested with conventionalolfactory tests (Sniffin’ Sticks Threshold, Discrimination, andIdentification test), but their perception of odor intensity wasimpaired. In general, odors were perceived as less intensecompared to the healthy controls. In contrast, their perception ofodor pleasantness was unremarkable. These preliminary findingssuggest that perceived intensity of suprathreshold odors may beimpaired following mTBI. To our knowledge, we are the first todemonstrate long-standing, albeit subtle, olfactory deficitsfollowing mTBI. Grant Acknowledgement: Supported byRGPIN 335938-08 awarded to JD by NSERC.#P3 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsVolatile biomarkers for human melanoma cellsJae Kwak 1 , Hakan Ozdener 1 , Michelle Gallagher 1 , Charles JWysocki 1 , Adam Faranda 1 , Amaka Isamah 1 , Steve SFakharzadeh 2 , Christopher J Miller 2 , George Preti 1,21Monell Chemical Senses Center Philadelphia, PA, USA,2Department of Dermatology, School of Medicine, University ofPennsylvania Philadelphia, PA, USADogs can be trained to localize not only melanoma samples buriedon the skin of healthy subjects, but also the areas with melanomafrom cancer patients. The skin lesions of melanoma and nevi canbe differentiated instrumentally (e.g. by a gas sensor array). Thesestudies suggest that skin tumors produce a different profile ofvolatile organic compounds (VOCs) than normal skin. However,the identity of the compounds distinguishing normal skin frommelanoma is not currently known. We analyzed the VOCsreleased from human melanoma and normal pigmented skincells (melanocytes), cultured in vitro, by employing solid phasemicroextraction (SPME) and gas chromatography/massspectrometry (GC/MS). There are significant, quantitativedifferences in the relative amounts of several compounds thatdistinguish normal melanocytes from melanoma cells as well aseach type of melanoma cells from one other. Thus, monitoringthese VOCs has the potential to be a useful screening tool formelanoma. This is currently being tested in melanoma patients.#P4 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsOlfactory function in childhood maltreatment andpost-traumatic stress disorderIlona Croy 1,2 , Julia Schellong 2 , Peter Joraschky 21Universitätsklinikum Carl Gustav Carus Department ofOtorhinolaryngology Dresden, Germany, 2 UniversitätsklinikumCarl Gustav Carus Department of Psychotherapie andPsychosomatic Medicine Dresden, GermanyBackground: Childhood maltreatment (cm) has often beenhypothesized to result in functional changes of amygdalae andorbitofrontal cortex. If such changes exist, we would expect aneffect of these changes on olfactory function in adults with ahistory of cm, because amygdalae and orbitofrontal cortex haveoutstanding importance for olfactory processing. Methods: Wecompared 31 depressive women with a history of cm, 28depressive women without cm, and 27 healthy women. ForP O S T E R SAbstracts | 27

comprehensive assessment of olfactory function we used the“Sniffin´ Sticks” odor threshold and odor identification test.Furthermore we analyzed chemosensory event related potentialsin response to pleasant and unpleasant olfactory stimuli andtrigeminal activation. Additionally participants answered aquestionnaire for current symptoms of posttraumatic stressdisorder (PTSD). Results: Contrary to our hypothesis we foundno significant difference between the cm-group compared to thetwo control groups. However, there was a significant correlationbetween current symptoms of PTSD and olfactory function.Following statistical adjustment for depressive symptoms asignificant correlation remained between PTSD symptoms andodor identification, N1 latencies in response to the unpleasanttrigeminal (CO 2 ) and olfactory (H 2 S) stimuli, and N1 amplitudesin response to the same unpleasant stimuli. Conclusions: Theresults indicate a preferred processing of unpleasant stimuli inpatients with PTSD - irrespective of the childhood history - andfit the information dissociation theory in PTSD. Because we didnot find changes in olfactory function depending on cm, theinfluence of current psychopathology appears to be of highersignificance to the amygdalae and orbitofrontal function than thechildhood history.#P5 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuits“Anosmic smell”: Residual olfactory function followinghemispherectomyJelena Djordjevic, Faye Pesenti, Alain PtitoMontreal Neurological Institute, McGill University Montreal,QC, CanadaHemispherectomy is a relatively rare neurosurgical procedure,done to treat intractable epileptic seizures, involving completeremoval or deafferentation of a whole cerebral hemisphere.We examined olfactory function in one subject who underwenthemispherectomy, and compared her performance to that of ahealthy control volunteer, matched for age and gender. DR is a31-year-old right-handed woman whose level of intellectualfunction is in the average range. At age 5, at onset of epilepticseizures, she was diagnosed with Rasmussen’s chronicencephalitis. At age 17, she underwent a right functionalhemispherectomy. We tested olfactory function separately ineach nostril, examining her detection thresholds, qualitydiscrimination, and identification, with Sniffin’ Sticks. In addition,we requested a confidence rating after each response, in order tocompare confidence levels associated with correct versus incorrectresponses. As expected, her olfactory performance was preservedwith the nostril contralateral to the removed hemisphere. Incontrast, she was considerably impaired when tested ipsilaterally.Notably, while her threshold and discrimination results were atchance, she was still able to identify stimuli, albeit with difficulty.Furthermore, she showed a normal divergence of confidencewithin each task : higher confidence was associated with correctresponses and lower confidence with incorrect ones, and this wasthe case both when tested ipsi- and contralaterally to the lesion.These results demonstrate residual rudimentary olfactory functionipsilaterally to the removed hemisphere, which we call “anosmicsmell” and they parallel the “blindsight” abilities previouslydocumented in this subject. Results are discussed in light of herpostoperative MRI findings.#P6 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsThe perception of malodors: An fMRI study of age and genderrelated differences between pre and post puberty subjectsThomas Hummel 1 , Arianne Baur 1 , Cornelia Hummel 1 ,Anita Chopra 21Smell & Taste Clinic, University of Dresden Medical SchoolDresden, Germany, 2 Unilever Research and Development PortSunlight Wirral, United KingdomAlthough learning, experience and socialisation strongly influencethe individual perception of odors, central nervous processing ofodorous stimuli in different stages of adolescence has to date onlyrarely been studied. In spite of frequent reports about age andgender modulating odor perception, fMRI has scarcely beenapplied to substantiate these differences. In this study, 20 righthanded subjects were grouped according to gender and age (prepuberty: 9 - 12 yrs. and post puberty: 17 20 yrs.) to build fourequally sized samples. By means of fMRI, patterns of cerebralactivation in pre and post puberty girls and boys after nasalstimulation with three malodors were compared(Androstadienone, 2-Methyl-3-Mercaptobutanol and H 2 S).Data analysis did not reveal significant gender differences, butactivation patterns were found to differ between age groups.While pre puberty subjects mainly showed activation of earlierprojection stages of odor processing, namely piriform cortex andamygdala, in post puberty participants, enhanced activation wasrevealed in neocortical areas (insula and medial and inferiorfrontal gyri). This finding may be interpreted in terms ofintegrative aspects of odor processing playing an important role inthe post puberty group. The pattern of enhanced neocorticalactivation could reflect a more advanced stage of social andcognitive development.#P7 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsOdor judgments in first episode and chronicschizophrenia patientsClaudia I. Rupp 1 , Georg Kemmler 1 , Thomas Walch 1 ,Arne W. Scholz 2 , Martina Klimbacher 1 , Theresia Lechner 1 ,Hartmann Hinterhuber 1 , Wolfgang W. Fleischhacker 11Innsbruck Medical University, Department of Psychiatry andPsychotherapy Innsbruck, Austria, 2 Innsbruck Medical University,Department of Otorhinolaryngology Innsbruck, AustriaThere is consistent evidence that schizophrenia patients haveolfactory dysfunction. Impairments in olfactory identification,quality discrimination as well as sensitivity are well described.There has been little investigation of olfactory judgments inschizophrenia, and the few findings are controversial. The aim ofthis study was to determine whether patients experiencing a firstepisodeschizophrenia and patients with chronic schizophreniadiffer in odor judgments. Olfactory judgment measures includedintensity, edibility, familiarity and hedonic ratings. Subjects wereasked to rate edibility, familiarity and hedonic about 16 everydayodors (real-world items) on visual 7-point rating scales. Half ofodors were edible, half not. Olfactory intensity judgments wereperformed using the odors from an identification task (Sniffin’Sticks). Unirhinal performance in olfactory judgments werecompared between young first-episode patients, young patientswith chronic schizophrenia and healthy controls similar in age28 | AChemS Abstracts 2009

and gender (all male). Our results demonstrate that only patientsexperiencing their first episode showed bilateral impairedfamiliarity and edibility judgments of odors by comparison withhealthy controls. No group differences were observed in intensityratings. Chronic schizophrenia patients, however, differedsignificantly in hedonic odor ratings from both, controls and firstepisode patients. These group differences remained significanteven after controlling for lower sensitivity in chronic patients.These findings indicate intact odor intensity in schizophrenia.Impairments in familiarity and edibility judgments are presentearly in the course of the illness, whereas disturbances in hedonicvalence of odors might be related to effects of medication orillness duration.#P8 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsOdor Discrimination in Mouse Models of SchizophreniaJennifer L. Hellier 1,2 , Nicole L. Arevalo 1,2 , Catherine E. Adams 3 ,Diego Restrepo 1,2,41Dept. of Cell & Developmental Biology, Univ. of ColoradoDenver Aurora, CO, USA, 2 Rocky Mountain Taste & SmellCenter, Univ. of Colorado Denver Aurora, CO, USA,3Dept. of Psychiatry, Univ. of Colorado Denver Aurora, CO,USA, 4 Program in Neuroscience, Univ. of Colorado DenverAurora, CO, USASchizophrenia is a psychiatric disease characterized by inaccurateperceptions of reality including deficits in odor discrimination.Previous studies have shown polymorphisms in the humanalpha7-nicotinic acetylcholine receptor (alpha7) promoter anddecreased expression of alpha7 in the hippocampus inschizophrenia. Mouse models of schizophrenia have similarpolymorphisms in the alpha7 promoter region and decreases inalpha7 expression in the hippocampus. However, it is not knownif olfactory deficits persist in animal models. Here we characterizealpha7 expression in the olfactory bulb (OB) and determine odordiscrimination of mouse strains (C57 and C3H) with alteredalpha7 expression (wild-type – WT; alpha7 heterozygousknockouts – HET; alpha7 homozygous knockouts – KO). Using[ 125 I] alpha-bungarotoxin binding, mean alpha7 expression in theOB was highest in C57 compared to C3H WT mice. Binding wassignificantly decreased in HET mice and no binding was found inKO mice (ANOVA, p

Combining both techniques we aimed to gain more insight aboutregions involved in generation of olfactory ERPs. Subjects andMethods: Eighteen hyposmic IPD patients of same age and samestage of disease (: ERP+: 3 patients = 1.5; 5 patients ≥ 2; 1 patient=3, vs. ERP -: 5 patients ≤ 1.5; 2 patients ≥ 2; 2 patient =3) wereexamined using olfactory ERPs. According to the detectability (+)or non-detectability (-) of ERPs patients were assigned into twogroups of 9 subjects each (ERP+: 6 women, 3 men; and ERP- :2women, 7 men) . Central activation during olfactory stimulationwas examined using fMRI. Results: Both groups, ERP+ and ERPpatientsshowed activity in areas relevant to olfactory processingsuch as amygdala, parahippocampal regions and inferior frontalgyrus. ERP+ patients activated additional frontal and temporalregions. Contrasts between both groups showed higher activity inERP+ patients, especially in amygdala, parahippocampal cortex,insula, cingulate gyrus, striatum and inferior temporal gyrus.Conclusion: The degree of central nervous activation in IPDpatients reflects the difference in olfactory function as depicted inthe presence or absence of an ERP. Moreover, the limitedactivation in the ERP- group in primary olfactory areas leads tothe assumption that further olfactory processing in IPD isseverely disturbed.#P11 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsScent marking and countermarking behaviors as a measureof olfactory communication in the BTBR T+tf/J inbredstrain, a mouse model of autismFlorence I. Roullet, Markus Wöhr, Mu Yang, Jacqueline N.CrawleyLaboratory of Behavioural Neuroscience- National Instituteof Mental Health Bethesda, MD, USAAutism is a neurodevelopmental disorder of unknown cause thatis usually diagnosed before 3 years of age. No consistentphysiological hallmarks of the disease have been identified so far.Diagnosis is currently based on three behavioral criteria: 1)abnormal reciprocal social interactions, 2) impaired verbal andnon-verbal communication, and 3) repetitive, restricted interests.Mouse models of autism provide translational strategies to testhypotheses about the causes and to develop treatments. Whileassays are available for social interaction and repetitive behaviorsin those models, there is a need for relevant methods to assesscommunication impairments. We are currently developingbehavioral tools to address specifically the question of olfactorycommunication in mice. The first task under developmentexamines scent marking in male mice, evoked by female urine.Ultrasonic vocalizations emitted by the male subject mice whilesniffing the female urine spot are simultaneously recorded. Forthis task, we compare sexually experienced male mice to sexuallynaïve male mice. The second task focuses on the territorialcountermarking behavior of male mice. After a first male has scentmarked an arena, he is removed and a second male is then placed.Countermarks from the second male are scored. Data will beshown from experiments using those two assays to compare astandard inbred strain that exhibits high sociability, C57BL/6J, toour best mouse model of autism, BTBR T+tf/J (BTBR). Ourlaboratory and other previously demonstrated that the BTBRinbred strain exhibits multiple social deficits along with repetitivepattern of behaviors that are analogous to the core symptoms ofautism. The present experiments explore the hypothesis thatBTBR traits also include olfactory communication deficits.#P12 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsTaste damage following radiation treatment for head andneck cancerHenrietta L. Logan, Linda M. Bartoshuk, Vicki D. Mayo,William M. MendenhallUniversity of Florida Gainesville, FL, USAPatients report taste damage following radiation treatment forhead and neck cancer. In addition, we recently found anassociation between reports of altered taste, elevated oral pain andthe presence of taste phantoms among 5-year survivors of headand neck cancer compared to a non-cancer comparison group(Logan et al, 2008). To further understand the extent of tastedamage from radiation treatment we used spatial taste tests on2-year cancer survivors (48 men and 13 women) and an age andsex matched non cancer comparison group (38 Men and 17women). NaCl, sucrose, citric acid and quinine were swabbed onloci innervated by the chorda tympani (CN VII) andglossopharyngeal (CN IX) nerves; whole mouth taste was testedas well. It was hypothesized that the 2-year survivors would showtaste damage at sites associated with the glossopharyngeal nervebecause of the location of the tumor and radiation treatment (baseof tongue and tonsil tumors). Results of t-tests (alpha levels wereadjusted for multiple tests) showed significantly lower ratingsfrom the cancer survivors compared to the control group forquinine, sugar, and citric acid at the circumvallate papillae but notNaCl. There were no significant differences between the twogroups for the fungiform papillae or whole mouth. Functionrelated oral pain but not spontaneous oral pain was significantlyhigher among the 2-year cancer survivors; the survivors alsoreported more taste phantoms. These findings support the tastenerve dis-inhibition hypothesis by showing that localized damageto the glossopharyngeal taste nerve associated with normal wholemouth taste as well as intensified oral pain and taste phantoms.#P13 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsThe use of odours as emotional triggers in the study ofdysfunctional brain regions in bipolar disorder –an fMRI studySimona Negoias 1 , Emilia Iannilli 1 , Stephanie Krueger 2 ,Johannes Gerber 3 , Thomas Hummel 11Smell & Taste Clinic, Department of Otorhinolaryngology ,University of Dresden Medical School Dresden, Germany,2Department of Neuroradiology, University of Dresden MedicalSchool Dresden, Germany, 3 Department of Psychiatry andPsychotherapy, Charité University Medicine Berlin, Campus MitteBerlin, GermanyAn emotional over reactivity is a trait characteristic of bipolardisorder. Exploring brain abnormalities underlying thisdysfunction is important for understanding the pathology ofbipolar disorder and identifying potential risk factors fordeveloping this disease. In this study we used fMRI to investigatethe brain activation of 11 euthymic bipolar patients exposed to2 hedonically different olfactory stimuli compared to a healthycontrol group matched for age, sex, and smoking behavior. Muchmore activated voxels in the anterior limbic network were foundin the Patients vs. Control contrast when presenting either thepleasant or the unpleasant odor. Olfaction seems to be aninteresting model for investigating abnormal patterns of brain30 | AChemS Abstracts 2009

activation in psychiatric disorders due to the overlap withemotional cerebral processing, resulting in immediate andmeaningful emotional experiences.#P14 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsMind over age – Social priming and olfactory functionEva C. Alden 1 , Amy R. Gordon 1 , Monica Hernandez 1 ,Mats J. Olsson 2 , Johan N. Lundstrom 1,31Monell Chemical Senses Center Philadelphia, PA, USA,2Department of Clinical Neuroscience, Karolinska InstituteStockholm, Sweden, 3 Department of Psychology, University ofPennsylvania Philadelphia, PA, USAPriming of the elderly social stereotype is known to inducechanges in subjects’ motor and cognitive function, resulting inreduced walking speed and impoverished memory performanceakin to those typically associated with the elderly population.To date, no study has explored whether social priming is alsocapable of modulating primary sensory functions. We exploredthe effects of social priming on olfactory function using abetween-groups design in which subjects were primed by viewingvisual and language stimuli of either a neutral (control; n= 18) orelderly (experimental; n= 18) theme before undergoing a batteryof motor, cognitive, and olfactory testing. Measures of walkingspeed were taken covertly as subjects traversed a standard lengthof hallway to the restroom, word recall scores were taken asmeasures of memory function, and sensitivity to n-butanol,odor discrimination, and 40-odor identification as olfactoryperformance measures. There were significant effects of socialpriming on both walking speed and memory function withexperimental subjects demonstrating a 10.77% decrease inwalking speed and 28.28% decrease in recalled words, relativeto control subjects. However, there were no significant differencesbetween groups in measures of olfactory sensitivity,discrimination, or identification. These data demonstrate thatalthough social priming affects motor and cognitive function,it has limited effects on primary olfactory function.#P15 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsFaster Cognitive Processing of Olfactory Stimuli in anActive Task, Even in Old AgeCharlie D. Morgan 1 , Krystin M. Corby 1 , Claire Murphy 1,21San Diego State University, Department of PsychologySan Diego, CA, USA, 2 University of California Medical CenterSan Diego, CA, USAsmelled the odor. Previous studies comparing active and passivetasks in the olfactory modality utilized longer ISIs of 45 or 60milliseconds and demonstrated no significant latency differencesbetween tasks for the P300. Repeated measures MANOVA wasutilized for statistical analysis. The current study demonstratesthat a 30 second ISI elicits significantly shorter P300 latencies inan active response condition compared to a passive responsecondition. Additionally this latency difference is consistent acrossthe lifespan. There were no significant age by response taskinteraction effects. The current study suggests that activelyattending to an olfactory stimulus leads to faster cognitiveprocessing of that stimulus, even in old age.#P16 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsFunctional Connectivity of Olfactory Processing During aHedonic Evaluation Task in Young and Older AdultsErin R. Green 1 , Lori Haase 1 , Claire Murphy 1,21San Diego State University/University of California, San DiegoJoint Doctoral Program in Clinical Psychology San Diego, CA,USA, 2 Department of Surgery, University of California,San Diego San Diego, CA, USAOlfactory function declines with age and research usingneuroimaging techniques has illustrated reductions in theactivation of brain regions involved in olfactory processing inolder compared to young adults. The objective of the presentanalysis was to examine differences in the recruitment offunctional networks involved in processing olfactory hedonicsin young (ages 18-30) and healthy older adults (ages 65+).Functional connectivity methods allow for the extraction ofassociations between various brain regions, illustrating therecruitment of an entire functional network involved in aparticular task. Comparisons can then be made between networkmodels among different populations. This analysis was run on thefunctional Magnetic Resonance Imaging time series during whichparticipants received .3ml of a citral solution and were asked torate the pleasantness of the odor. The resulting patterns ofconnectivity suggest age-related disturbances in the recruitmentof networks related to olfactory processing during evaluation ofpleasantness. Identifying differences in functional circuitsinvolved in hedonic evaluation of food-related stimuli in youngand older adults may increase understanding of age-relateddifferences in the experience of food reward as well as variousnutritional problems that occur with aging.#P17 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsP O S T E R SThe P300 cognitive event-related potential (ERP) was elicitedwith a single stimulus paradigm for olfactory stimuli in separateactive (attend) and passive (ignore) task response experimentsutilizing an inter-stimulus interval (ISI) of 30 seconds. Participantswere young, middle age and older, healthy adults, all free ofcognitive impairment. Amyl acetate was administered via anolfactometer for a duration of 200 milliseconds over 20 trials foreach task condition. The passive condition was always presentedprior to the active task. In the passive task subjects wereinstructed to ignore the stimuli and sit and daydream. In the activetask subjects were instructed to press a button as soon as theyFunctional Connectivity during an olfactory recognitionmemory paradigm is associated with task performanceand the e4 allele of the apolipoprotein E (ApoE) geneLori Haase 1 , Erin Green 1 , Claire Murphy 1,21SDSU/UCSD Joint Doctoral Program in Clinical PsychologySan Diego, CA, USA, 2 Department of Surgery, UCSD San Diego,CA, USAThe e4 allele of the apolipoprotein E (ApoE) gene is the strongestgenetic risk factor for Alzheimer’s disease (AD). The e4 allele isassociated with decrements in memory and in olfactory function.Abstracts | 31

Previous fMRI studies indicate that these processes engage themedial temporal lobes (MTL) and the frontal lobes. The MTL isthe initial site of neuropathology in AD. Thus, we expected adisruption in communication between MLT and frontal lobes ine4+ individuals. Moreover, we hypothesized that a task thatengages both regions, i.e., odor recognition memory, would beparticularly sensitive to loss of connectivity and thus fordistinguishing between e4+ and e4- persons. Functionalconnectivity methods allow for the investigation of the strength offunctional associations between different brain regions with theunderlying assumption that functional networks underlie specificcognitive processes. The purpose of this study was to investigatedifferences in functional connectivity during odor memoryprocessing between e4+ and e4- individuals. Prior to fMRIscanning, participants were presented with 16 odors. During twoscans, names of odors presented before scanning (targets) or notpresented (foils) were shown. Participants discriminated betweentargets and foils. The results indicate that there were greaterassociations between bilateral frontal lobes and MTL duringcorrect rejection of foils and correct identification of targets fore4+ relative to e4- individuals. These findings suggest thatprocesses that recruit additional neuronal populations (e.g.,compensation, alternative strategies) may facilitate performance inindividuals who are genetically at risk for AD. Differences infunctional connectivity that distinguish between e4+ and e4-individuals may be useful in predicting incipient dementia.#P18 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsOlfactory, but not Gustatory Function, correlates withBMI and Depressive Symptoms in the ElderlySanne Boesveldt 1 , Thomas Hummel 2 , Stacy Tessler Lindau 3 ,Johan N Lundstrom 1,41Monell Chemical Senses Center Philadelphia, PA, USA,2Dept. of Otorhinolaryngology, University of Dresden MedicalSchool Dresden, Germany, 3 Dept. of Obstetrics and Gynecology,University of Chicago Chicago, IL, USA, 4 Dept. of Psychology,University of Pennsylvania Philadelphia, PA, USAThe decline of chemosensory function known to occur withadvancing age has, in turn, been linked to aging-related anorexiaand other associated diseases. Few studies, however, haveinvestigated the interaction between chemosensory function andhealth in the aged population. The National Social Life, Healthand Aging Project explores the interactions between physicalhealth and sensory function using a national probability sampleof community-residing men and women, aged 57-85 years. Weexamined chemosensory function and its relation to body massindex (BMI, kg/m 2 ) and depressive symptoms in this population.Olfactory function was assessed using a five-item odoridentification test. Odor ID was separated into food (peppermint,fish, orange) and non-food (rose, leather) items. Four tasteimpregnatedstrips of filter paper (sweet, sour, bitter, salty) wereemployed to assess gustatory function. Correlation coefficientswere computed to determine the correlation between olfactory orgustatory function and BMI or depressive symptoms (measuredby the CES-D). The prevalence of ageusia was 14.8%. ‘Sour’ wasidentified correctly least often (39.4%). The prevalence offunctional anosmia was 2.7%. Food items were better identifiedthan non-food items (88.2% vs 73.7%, p

the e4 allele. The ApoE e4 allele is also associated with increasedrisk for Alzheimer’s disease. When measuring olfactory eventrelatedpotentials (OERPs), the third peak (P3) is considered to bea cognitive component. The purpose of this study was toinvestigate the effects of age and ApoE status on the P3component of OERPs. Subjects in age groups of young (18-28years old), middle age (45-56), and older (65 +) were administeredan olfactory detection task to elicit the OERP. Participants wereinstructed to respond as quickly as possible after smelling theodor by pressing a button. The stimulus was amyl acetatepresented every 30 seconds by olfactometer. Statistical analyseswere performed using a multivariate analysis of variance. Nosignificant effects for P3 amplitude were found. There was nosignificant effect of ApoE e4 status on latency for the young ormiddle age groups. In the older group, ApoE e4 positiveparticipants had significantly longer latencies than their negativecounterparts. They also had longer latencies than the positiveyoung and middle age participants. The effect size in the currentstudy is larger than previous studies that previously demonstratedincreased latencies for this population likely due to the decreasedinter-stimulus interval to 30 seconds from 45 seconds. The shorterinter-stimulus interval increased the difficulty of the task bygiving the participant less time to recover from each stimulus.#P21 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsInfluence of Cognitive Status on Olfactory ThresholdVariabilityBrittany N. Carlisle 1 , Jason M. Bailie 1 , Lloyd Hastings 2 ,Katie Pointer 1 , Katie VanDeGrift 1 , Robert A. Frank 1,31University of Cincinnati Cincinnati, OH, USA, 2 OsmicEnterprises Cincinnati, OH, USA, 3 CompuSniff Cincinnati,OH, USADetection thresholds have been used by a number of investigatorsinterested in the effects of neurodegenerative disorders andnormal aging on the olfactory system. Odor thresholds areoccasionally compared to performance on more cognitivelydemanding tests under the assumption that threshold measures areonly minimally affected by disease or age-related deficits inmemory or other cognitive functions, and therefore provide abetter measure of “pure” sensory function. We recentlydemonstrated that although thresholds are less subject to theinfluence of cognitive changes as compared to odor identification,thresholds are influenced by cognitive variables such as cognitiveprocessing speed. The current study examined the influence ofcognitive status on the olfactory abilities of young and olderadults as measured by detection thresholds. The main question ofinterest was whether the ability to discriminate between the twosubject groups would change if the effects of cognitive status weretaken into account. A sample of 34 healthy, community-dwellingolder adults was compared to a sample of 31 healthy, youngadults. Odor detection thresholds for butanol were determined onfour occasions for each group and supplemented byneuropsychological testing. The two groups of participants wereseparated easily using the average of the four thresholds with thedifference between the groups accounting for 25% of the variancein thresholds. Using the Montreal Cognitive Assessment (MoCA)score as a covariant sharply reduced the difference between thegroups, and lower the variance accounted for by the group effectto 8%. These results provide evidence that mild cognitive deficitsamong older adults can augment differences in odor thresholdmeasurements obtained from younger and older people.#P22 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsOlfactory Perceptual Correlates of b-Amyloid PlaqueBurden in Alzheimer’s Disease Mouse ModelsDaniel W. Wesson 1 , Efrat Levy 2,3 , Ralph A. Nixon 2,3 ,Donald A. Wilson 1,31Emotional Brain Inst., Nathan Kline Inst. for Psych ResearchOrangeburg, NY, USA, 2 Ctr. for Dementia Research, NathanKline Inst. for Psych Research Orangeburg, NY, USA, 3 New YorkUniv School of Medicine New York, NY, USAAlzheimer’s Disease (AD) often results in a substantial loss inolfactory perceptual acuity – the cause of which is unknown.To begin addressing this, we explored odor perception in twoAD mouse model lines, which express mutated forms of humanamyloid precursor protein (APP) and consequently display - bamyloid (Ab) plaques characteristic of AD. We found a significantolfactory behavioral phenotype in both lines of AD mice. Whileall mice showed a robust investigation of novel odors, AD mouselines investigated novel odors for greater durations than agematchedcontrols and showed an increased latency to habituateto novel odors. These behavioral results suggest a deficiency innormal olfactory coding similar to that reported clinically inhumans with AD. Given this phenotype, we are currentlyexamining whether odor perceptual deficits correlate with plaqueload in the olfactory bulb and piriform cortex within the samemice. If so, then these results may be consistent with an importantrole for Ab or other Ab pathogenic factors within olfactorycircuits on odor perceptual deficits in AD.#P23 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsToxin-Induced Chemosensory Dysfunction:A Case Series and ReviewWendy M. Smith 1 , Terence M. Davidson 1,2,3 , Claire L. Murphy 1,41Department of Surgery, University of California, San DiegoSan Diego, CA, USA, 2 Continuing Medical Education, Universityof California, San Diego School of Medicine San Diego, CA, USA,3VA San Diego Healthcare System San Diego, CA, USA, 4 SanDiego State University San Diego, CA, USAToxic chemical exposures, both acute and chronic, are estimatedto account for 1-5% of all olfactory disorders. Likewise, tastebuds are susceptible to direct chemical injury due to theirvulnerable position in the oral cavity and oropharynx. This areahas been a relatively neglected topic in the medical literature, withprevious publications limited primarily to single case reports orbroad reviews. We describe 8 cases here that illustrate differentaspects of the diagnostic and therapeutic approach to patientswith this disorder. Cases were selected for inclusion based on aretrospective chart review of patients who presented to auniversity-based nasal dysfunction clinic with toxin-inducedolfactory or gustatory dysfunction between January 1985 andDecember 2008. Patient ages ranged from 17-67 years (mean 41.6years). Etiology of chemosensory impairment included exposureto ammonia, isodecanes, permanent wave chemicals,chemotherapy, gasoline and intranasal zinc. Workup includedcomplete history, medical examination, psychophysical testing,and imaging. Symptom ratings, odor threshold, odoridentification, and/or University of Pennsylvania SmellIdentification Test were used to assess olfactory impairment.P O S T E R SAbstracts | 33

Five out of the 8 patients (62.5%) presented with olfactorydysfunction alone, 1 patient (12.5%) presented with gustatorydysfunction alone, and 1 patient (12.5%) presented with bothsmell and taste loss. Only 1 patient (12.5%) reported parosmias.Olfactory testing revealed mild-to-moderate hyposmia in 1patient (12.5%) and severe hyposmia-to-anosmia in 6 patients(75%). Both patients who reported taste loss had hypogeusiaupon testing. This case series helps illustrate the wide spectrumof this disorder and provides a framework for the workup andtreatment of these patients.#P24 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsGene-targeted deletion of E2F1 evokes olfactory deficits,memory loss, and increased anxietyDavid R. Marks, Ying Wang, Kelly Jordan-SciuttoUniversity of Pennsylvania Philadelphia, PA, USAAdult neurogenesis (ANG) plays a substantial role in themaintenance and function of the central nervoussystem. Throughout the process of ANG, tight control of cellcycle, proliferation, and apoptosis is maintained via cell cycleproteins. Specifically, the cell cycle protein E2F1 plays animportant role during generation and replacement of neurons inthe adult brain, as demonstrated by a substantial reduction ofANG in the olfactory bulb and dentate gyrus (DG) of E2F1knockout mice (KO). The OB and DG are critical in olfactionand memory, hence we hypothesized that E2F1 KO mice maydevelop deficits in olfactory ability and memory. Wild-type (WT)and KO mice of five age ranges were subjected to general anosmiaand object memory behavioral paradigms to assess basic olfactoryand memory function. E2F1 KO mice displayed a threefoldincrease in retrieval time of a scented object versus WT mice,suggesting that age-dependent deficits in olfaction and/ormotivation arise. Counts of olfactory sensory neurons wereperformed to determine if peripheral neuron loss could beinvolved, however, there were no reduction in numbers normorphological changes. Additionally, all WT age groupsdemonstrated adequate short-term memory (1 hour), whereasE2F1 KO mice object memory recognition deteriorated overtime, failing tests at postnatal day ages 270 and 365. Interestingly,E2F1 KO mice displayed incessant digging during tests, so marbleburying and light/dark box (LDB) behavior were assayed todetermine anxiety levels. E2F1 KO mice buried significantly moremarbles than WT mice in all age groups, and spent significantlyless time in the light chamber of the LDB in 4/5 age groups. Thus,E2F1 KO mice display a sequence pattern of early and continuedanxiety, followed by deficits in olfaction and then memory.#P25 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsSocial Anxiety and Reduced Recruitment of OrbitofrontalCortex to Human Social Chemosensory CuesKathy Zhang, Wen Zhou, Denise ChenRice University Houston, TX, USASocial anxiety refers to the prevalent and debilitating experience offear and anxiety of being scrutinized in social situations. It arisesfrom both adverse social conditioning and inherent factors likeshyness. Previous research focuses on negative emotions insocially anxious patients induced by visual and auditory socialcues, and posits a dysfunctional orbitofrontal-amgydala circuitryas a primary etiological mechanism. Here using functionalmagnetic resonance imaging (fMRI) and a unique type of socialstimuli, airborne human social chemosensory cues that areinherently social and ubiquitously present, but not typicallyconditioned to trigger subjective anxiety, we show that individualswith elevated social anxiety demonstrated a reduced recruitmentof the orbitofrontal cortex to social chemosensory cues. Noreciprocal activity in the amygdala was observed. Our findingspoint to an internal neural substrate underlying social anxietyindependent of previous adverse social conditioning fromexperience, thereby providing the first neural evidence for theinherent social aspect of the enigmatic phenomenon.#P26 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsToxoplasma gondii infects olfactory structures in the mouse:a possible mechanism for host maniplulation by influencingolfactory functionAnn E. Jorgensen 1 , Corrie N. Hiltbrand 2 , Gustavo Arrizabalaga 3 ,Mark D. Lavine 3 , Kevin R. Kelliher 11Dept. Biological Science, University of Idaho Moscow, ID, USA,2Dept. Biological Sciences, Brigham Young University IdahoRexburg, ID, USA, 3 Dept. Microbiology, Molecular Biology andBiochemistry, University of Idaho Moscow, ID, USAToxoplasma gondii (T. gondii ) is a protozoan parasite that infectsmost warm-blooded vertebrates including humans. Once in thebody T. gondii can enter the central nervous system where itforms latent cysts. While generally thought to be benign, T. gondiiin its latent form has been shown to adversely affect predatoravoidance in rodents. This is one of the few examples of a parasitemanipulating the behavior of a vertebrate host. It is still unclearhow T. gondii exerts its effects on its host. Here we explorewhether T.gondii affects a host’s behavior through a directmanipulation of the olfactory system. Using C57/Blk6 male micethat were chronically infected with T. gondii we observed twobehavioral abnormalities associated with olfactory function.First, we observed a reduced avoidance to a predator odor (caturine) in T. gondii infected mice compared to sham infected mice.T. gondii infected mice spent significantly more time investigatingcat urine than sham mice in a two choice preference test ( t-test,P

including the olfactory epithelium, olfactory bulbs and the medialamygdala. These results are the first step towards showing that T.gondii cysts directly influence the olfactory system leading to analtered behavioral response to predator odors.#P27 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsSexual dimorphism in olfactory bulb structureWilli Bennegger 1 , Elke Weiler 21Maria-von-Linden-Schule, Heckentalstraße 86 D-89518Heidenheim, Germany, 2 Faculty of Medicine, Institute ofPhysiology, Department of Neurophysiology, Ruhr-UniversityD-44780 Bochum, GermanySexual dimorphism in mammals is often observed in the accessoryolfactory system, however, this system is rudimentary in speciessuch as the American mink. Thus, we were interested, if sexdependentstructural differences exist in the main olfactorysystem. Olfactory bulbs of adult American minks color-variety“standard” (Neovison vison var. atratus) were processedhistologically and always the right bulb analyzed with amorphometric system using weight/volume correction factors.The olfactory bulb is significantly bigger in males (152mm 3 )compared to females (107mm 3 ), however, females are muchsmaller than males and so is their absolute brain weight (m 11.51g;f 8.43g). Thus, the bulb-portion on the whole brain is similar(m 1.37%; f 1.32%). On the other hand, the brain relative to thebody mass is much bigger in females (0.85%) compared to males(0.55%), resulting in significantly different bulb/body ratios (m0.0076%; f 0.0112%). Sex-dependent differences exist also in theproportion of the neuronal layers: In males, the olfactory filacomprise the major portion of all layers (26.9%) but only 17.7%in females, where the majors are granule cell (GCL 28.8%) andexternal plexiform layer (EPL 22.8%) overwhelming theproportions in males (GCL 21.7%; EPL 19.2%) significantly.The mitral cell layer is significantly thicker in males (4.7%) thanfemales (3.5%).This indicates that the fila layer is related more tooverall body size (increase in the olfactory sheet / axon numbers)whereas the information processing GCL and EPL is related tothe brain size. This suggests also, that information processing ismuch more complex in females and to sustain the extended GCLthere might be a higher neurogenesis. Therefore, a significantsexual dimorphism in the main olfactory bulb exists, notreported before.#P28 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsHeterogeneous Sensory Innervation of IndividualNecklace GlomeruliRenee E. Cockerham, Adam C. Puche, Steven D. MungerDepartment of Anatomy and Neurobiology, University ofMaryland School of Medicine Baltimore, MD, USAThe mammalian nose employs several olfactory subsystems torecognize and transduce diverse chemosensory stimuli. Thesesubsystems differ in their anatomical position within the nasalcavity, their targets in the olfactory forebrain, and thetransduction mechanisms they employ. Here we report thatthey can also differ in the strategies they use for stimulus coding.Necklace glomeruli are the sole main olfactory bulb (MOB)targets of an olfactory sensory neuron (OSN) subpopulationdistinguished by its expression of the receptor guanylylcyclase GC-D and the phosphodiesterase PDE2, and by itschemosensitivity to the natriuretic peptides uroguanylin andguanylin and the gas CO 2 . In stark contrast to the homogeneoussensory innervation of canonical MOB glomeruli from OSNsexpressing the same odorant receptor (OR), we find that eachnecklace glomerulus of the mouse receives heterogeneousinnervation from at least two distinct sensory neuron populations:one expressing GC-D and PDE2, the other expressing olfactorymarker protein (OMP). In the main olfactory system it is thoughtthat odor identity is encoded by a combinatorial strategy andrepresented in the MOB by a pattern of glomerular activation.This combinatorial coding scheme requires functionallyhomogeneous sensory inputs to individual glomeruli byOSNs expressing the same OR and displaying uniform stimulusselectivity; thus, activity in each glomerulus reflects thestimulation of a single OSN type. The heterogeneous sensoryinnervation of individual necklace glomeruli by multiple,functionally distinct, OSN subtypes precludes a similarcombinatorial coding strategy in this olfactory subsystem.Instead it suggests that the necklace glomeruli could serve ascoincidence detectors for multiple chemosensory stimuli.#P29 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsSpatial analysis of olfactory bulb activity in the sea lampreyWarren W Green 1 , Sana Ahmed 1 , Dominique Derjean 2 ,Réjean Dubuc 2 , Barbara S Zielinski 11Department of Biological Sciences, University of WindsorWindsor, ON, Canada, 2 Centre de Recherche en SciencesNeurologiques, Département de physiologie, Université deMontréal Montréal, QC, CanadaThe sea lamprey (Petromyzon marinus) uses olfaction todetect a variety of odours that induce movement and searchingbehaviours. The peripheral olfactory organ of sea lamprey iscomprised of the main olfactory epithelium (MOE) and theaccessory olfactory organ (AOO). Neural connections from theAOO project solely to the medial region of the olfactory bulb(OB) while projections from the MOE are distributed to allglomerular regions. Our goal is to examine odour input specificityand processing in the OB of sea lamprey as it relates to behaviour.To that effect, we examined the morphological characteristics ofthe MOE and AOO as well as the organization of odourprocessing in the OB. The peripheral olfactory organ ofmetamorphic, parasitic, and migratory adult lamprey wasdissected, sectioned, and the relative area of the MOE andAOO was calculated. The proportion of AOO in the peripheralolfactory organ increased from 22% in metamorphic lamprey toupwards of 30% in parasitic and migratory adult sea lampreyindicating an increase in input from the AOO to the OB duringadult life stages. Additionally, multi-unit action potentials inresponse to odours were recorded in the OB of the live ex vivobrain of parasitic and migratory adult sea lampreys. Actionpotential frequency increased in the medial OB in response to bileacids and the lamprey pheromone 3KPZS. Action potentialfrequency also increased in the lateral and ventral-lateral OB inresponse to basic amino acids and 3KPZS, respectively. Theseresults indicate that odour input and processing in the medialOB is important for responding to behaviourally-relevant odours.Funding provided by the GLFC and NSERC.P O S T E R SAbstracts | 35

#P30 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsSpatial Representations of Natural Odor Objects Acrossthe Glomerular Layer of the Rat Olfactory BulbBrett A. Johnson, Joan Ong, Michael LeonDept. of Neurobiology & Behavior, UC Irvine Irvine, CA, USAWe previously have determined glomerular responses to 365monomolecular odorants, using uptake of 2-deoxyglucose toquantitatively assess activity across the entire rat olfactory bulb.To determine how these response patterns compare to responsesevoked by more natural odor stimuli, we now have mappeduptake during exposures to vapors arising from a variety ofobjects that might be important to rodents in the wild. Sixteendistinct stimuli ranging from possible food sources such as fruits,vegetables, and meats to environmental objects such as grass,herbs, and tree leaves were chopped or homogenized and thentheir vapors introduced into an air stream in the same manner aswe used previously for pure odorant chemicals. The natural odorobjects evoked robust and surprisingly focal patterns of 2-deoxyglucose uptake that in some cases were closely related topatterns evoked by known major monomolecular componentsthat are represented in our archive, but that in other cases weremore simple than might have been predicted given the multiplicityof components that must have been present in the vapors. Thesedata suggest the possibility of important mixture responseinteractions and provide a foundation for understanding theneural coding of natural odor stimuli.#P31 Poster session I: Chemosensory disorders, modelsand aging/Central chemosensory circuitsAnalysis of responses to musk odorants in olfactory sensoryneurons and in the main olfactory bulbMika Shirasu, Kazushige TouharaDepartment of Integrated Biosciences, The University of TokyoChiba, JapanMusk odorants are widely utilized in various perfumes because oftheir fascinating aminalic note. They exhibit similar odorcharacters despite their different chemical structures such asmacrocyclic, nitro and polycyclic moieties. To elucidate themechanism of musk odor perception, we investigated the responsepatterns of mouse olfactory sensory neurons (OSNs) and themain olfactory bulb (MOB) to musk odorants. In Ca 2+ imaging,68 neurons out of ~3000 dissociated OSNs responded to eugenol,whereas only 4 neurons responded to muscone, one ofmacrocyclic musk odorants. We next examined responses to muskodorants in the MOB using OMP-spH mice. No responsiveglomerulus was found in the dorsal and lateral regions of MOB.Then, we performed unilateral bulbectomy to image responses inthe medial region of MOB. This surgical technique enabled us toobserve a large part of the medial region of MOB, the area thathad not been imaged previously. Interestingly, only a fewglomeruli in the medial region showed responses to muscone.The muscone-responsive glomeruli did not respond to nitromusks, polycyclic musks and other classes of odorants such asaldehydes, acetates and benzenoid compounds. Using c-Fosexpression as a marker for odor-induced neuronal activity in theglomerular layer of the MOB, we analyzed spatial patterns of c-Fos positive glomeruli that were stimulated with musk odorants.c-Fos induction by muscone was observed around only a fewglomeruli that were located in a region very similar to thoseobtained by the bulbar imaging. Our findings indicate thatmuscone appears to be recognized by a few narrowly-tuned ORsand muscone activates a few glomeruli in the restricted region ofthe medial MOB in mice.#P32 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsInput Driven Synchrony of Oscillating OlfactoryReceptor Neurons: A Computational Modeling StudyIl Park 1 , Yuriy V. Bobkov 2 , Kirill Ukhanov 2 , Barry W. Ache 2,3 ,Jose C. Principe 11Department of Biomedical Engineering, University of FloridaGainesville, FL, USA, 2 Whitney Laboratory, Center for Smelland Taste, and McKnight Brain Institute, University of FloridaGainesville, FL, USA, 3 Departments of Zoology and NeuroscienceGainesville, FL, USATemporally structured activity in bursting and/or oscillatingneurons can be utilized to embed the temporal structure ofsensory input into an instantaneous population code. Wehypothesize that spontaneously bursting olfactory receptorneurons (ORNs) reported earlier by our group can extracttemporal features of the odor signal. We showed that, at least inlobster, each such ORN responds to a narrow range of stimulusfrequencies based on their spontaneous bursting discharge andphase dependent response to odor stimulation. A heterogeneouspopulation of such ORNs could encode a wide spectrum ofstimulus intermittency and also increase the reliability ofencoding. Computational model based on a modified renewalprocess was extrapolated from experimental recordings fromsingle lobster ORNs, and used to generate population responsesto a stimulation pattern. Simulation and analytical methods wereused to obtain the probability of various temporal patterns ofresponse. A homogeneous population showed synchronizationdynamics which changed in a stimulus frequency dependentmanner and could be enhanced, maintained, or depressed. In theabsence of stimulation, the population quickly approached theasymptotic pattern. To test if the heterogeneous population couldactually encode stimulus intermittency, a neural decoder was builtusing machine learning. We suggest a biologically plausible neuraldecoder based on a simple integrating neuron.#P33 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsIncrease in Number of Androgen Receptor ImmunoreactiveCells in the Medial Amygdala of Male Hamsters in Responseto Chemosensory InputCamille B Blake, Michael MeredithFlorida State University, Department of Biological Science,Program in Neuroscience Tallahassee, FL, USAIn many species, including hamsters, mating behavior isdependent on integration of chemosensory and hormonal cues.Chemosensory stimuli are detected by vomeronasal system,which projects to many regions that contain steroid receptors,including the medial amygdala (Me). Sexual behavior is alsofacilitated in male hamsters by direct action of testosterone withinthe medial amygdala. Me can be subdivided into anterior (MeA)36 | AChemS Abstracts 2009

and posterior (MeP), which are differentially activated bydifferent types of chemosignals. Conspecific stimuli activateMeA and MeP, while heterospecific stimuli only activate MeA.Furthermore, chemosensory stimuli with different socialsignificance may differentially activate the dorsal and ventralsubdivisions of MeA and MeP. Therefore, it is likely that steroidreceptors facilitate stimulation of Me by different types ofchemosensory stimuli. We examined activation, using Fos proteinexpression, of androgen receptor (AR)-containing cells in Me byheterospecific and conspecific stimuli with different socialrelevance (i.e., reproductive, competitive). Surprisingly, inresponse to chemosensory stimulus exposure, the number of ARimmunoreactive(IR) cells was significantly different from controland between stimuli with different social significance. Activationof AR-containing cells was also significantly different fromcontrol and between the different stimuli. These effects may bedue to acute increases in testosterone that occur in response tochemosignal exposure. Thus, castrated males with testosteronereplacement treatment are currently being tested in order toeliminate the possible testosterone feedback that occurs inresponse to chemosensory stimulus exposure.#P34 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsCytokine profiles in nasal lavage fluid of patients withchronic rhinosinusitisM. Hakan Ozdener 1 , Karen K Yee 1 , Beverly J Cowart 1 ,Aldona A Vainius 1 , Pu Feng 1 , Nancy E Rawson 1, 21Monell Chemical Senses Center Philadelphia, PA, USA,2WellGen, Inc North Brunswick, 08902, NJ, USAChronic rhinosinusitis (CRS) is an inflammatory condition of thenose and the paranasal sinuses characterized by an infiltration ofinflammatory cells, with associated edema, pain, and congestion,that significantly impairs quality of life and, in approximately 1/3of cases, impairs olfactory sensitivity. Inflammation is a necessaryaspect of the response to a foreign irritant or infection, and undernormal conditions triggers recovery and regeneration. In someindividuals, normal anti-inflammatory counter-regulatorypathways fail to activate sufficiently to resolve the inflammatoryprocess, and the reasons for this failure are not understood.Complete understanding of the nasal inflammatory processrequires measurement of multiple cytokines simultaneously. Inthis study, we aimed to examine the level of cytokines in nasallavage fluid obtained from the initial visit of patients diagnosedwith CRS (n=64) and healthy controls (n=26). A multiplex assay(Beadlyte, Millipore) was used for simultaneous quantification of19 cytokines. Variation was greater among patients, and levels ofIL2, IL4, IL13, IL15, IL1beta, MIP1alpha and Rantes were belowthe limit of detection in too many samples for reliablecomparison. Levels of IL8 were significantly elevated in CRSpatients relative to controls, and similar trends were observed forEGF, eotaxin, GRO and MCP1. Analyses of these data in relationto tissue degradation and patient outcomes may aid in theprediction of olfactory loss or disease resolution.#P35 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsVoltage-sensitive dye imaging of odor evoked activitypatterns in the trigeminal ganglion in vivoMarkus Rothermel 1,3 , Benedict Ng 2 , Hanns Hatt 1,3 , Dirk Jancke 21Lehrstuhl für Zellphysiologie , Ruhr-Universität Bochum,Germany, 2 Lehrstuhl Allgemeine Zoologie und Neurobiologie,Kognitive Neurobiologie, Bernstein Group for ComputationalNeuroscience, Ruhr-Universität Bochum , Germany,3Graduiertenkolleg GRK736 “Development and Plasticity of theNervous System: Molecular, synaptic and cellular mechanisms”Bochum , GermanyChemosensation from the mammalian nasal cavity ispredominantly mediated by two independent neural systems, theolfactory and the somatosensory (trigeminal) system. Opticalimaging techniques have thus far added significant knowledgeregarding the functional organization of information processing atthe level of the olfactory bulb. In contrast, due to the difficulty inaccessing trigeminal ganglia somata and nerve fibersexperimentally, a direct visualization of evoked populationactivity in the trigeminal ganglion in vivo remained elusive,leaving questions about the spatio-temporal representation ofodor related stimuli in the trigeminal ganglion unexplored.We established a preparation that allows high-resolutionrecording of optical signals arising from a large region of the rattrigeminal ganglion in vivo, using voltage-sensitive dye imaging.Stimuli were individually delivered by a specialized custom-madeolfactometer. Tested substances include CO 2 as a pure painactivator, odorants known to have a strong trigeminal component,as well as classical olfactory stimuli. Our data indicate aprototypical activation pattern related to a painful CO 2 stimulus.Stimulation with Ethanol, an odorant with a strong trigeminalcomponent produced an activation that showed high similarity tothis “pain”-pattern. Moreover the Ethanol map included uniqueactivation spots that might code for odor identity. In contrastclassical olfactory stimuli elicited activation patterns clearlydistinct from such “pain”-pattern. In conclusion this studyprovides first evidence that coding odor information might not bea feature unique to the olfactory system, but to some extent alsopossible via the trigeminal nerve.#P36 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsMicroglial response in the nucleus of the solitary tract afterchorda tympani nerve injuryDianna L Bartel, Thomas E FingerRocky Mtn Taste & Smell Ctr, Neurosci Prog,Univ Colo Denver Med Sch Aurora, CO, USAFollowing transection of the chorda tympani (CT), the nervereinnervates peripheral targets to permit regeneration of tastebuds. Despite the peripheral recovery, there remains persistentalterations of gustatory terminal fields in the nucleus of thesolitary tract (nTS), the primary gustatory nucleus in thebrainstem (Reddaway and Hill, AChemS abstract 2007 #516).In primary sensory nuclei of other systems, peripheral nervedamage provokes changes in microglial populations which may beinvolved in resultant synaptic remodeling. The gustatory systemremains unexplored regarding this possibility. We sought to testwhether microglia in the nTS respond to unilateral transection ofP O S T E R SAbstracts | 37

the CT. In adult mice, the CT was sectioned in its course via themiddle ear. The mice survived for various periods (1-30 days;n=4,5 at each time). Immunohistochemical staining for microgliausing Iba1 (cytoplasmic calcium binding protein specific formicroglia) reveals a dramatic increase in the number of stainedmicroglia in the ipsilateral nTS at 2 days post lesion. Microglialcell counts on the uninjured side of the nTS are not significantlydifferent from those of uninjured animals. Further, the microgliaon the injured side have an altered morphology. In normalanimals, Iba1 staining shows microglia with thin, highly ramifiedprocesses and smooth nuclei indicative of a resting state. On theinjured side, microglia in the nTS have short, thick processes and amore ‘ragged’ nuclei, a morphology typical of active microglia. Inthis state, these cells are capable of releasing a variety of secretorymolecules and becoming phagocytic. We also tested whethermicroglia proliferate locally in the nTS or are being recruited fromthe hematopoetic system in response to the peripheral injury.#P37 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsConvergent Innervation Patterns of the ChordaTympani and Glossopharyngeal Nerves onto Nucleusof the Solitary Tract Projection NeuronsJames A. Corson, Alev ErisirUniversity of Virginia Charlottesville, VA, USAThe innervation patterns of gustatory responsive nerves in therNTS is relatively unknown. We aimed to identify putativesynapses between either chorda tympani (CT) orglossopharyngeal (IX) nerves and individual projection neurons inthe rostral nucleus of the solitary tract (rNTS). Biotinylateddextran amine (BDA) was injected into the waist region of theparabrachial nucleus to retrogradely fill projection neurons in therNTS. Subsequently, CT was labeled with tetramethylrhodamineand IX with Cascade Blue and allowed 48 hours to transport.After perfusion and tissue sectioning, BDA was bound withstreptavidin Alexa488, resulting in triple fluorescently-labeledtissue. Sections containing CT and IX terminal fields as well asfilled projection neurons were then imaged at 90x on a laserscanning confocal microscope. The images were thendeconvolved, the dendritic trees reconstructed from multipleconfocal z-stacks, and the cell visualized in 3-dimensions. Thedendritic trees were traced and any contacts between the labelednerves and the cell identified. From these diagrams, innervationpatterns were ascertained for neurons that received convergentinput from CT and IX nerves. The majority of the imagedneurons received convergent input, often onto the same dendritictree. Both multipolar and bipolar projection neurons wereanalyzed and further classified based on their dendritic branchingpatterns as well as location in the rNTS. Further, innervationpatterns for each neuron were also examined, such as the distanceof the input from the soma and the clustering of like-inputs. Thisis the first anatomical demonstration and analysis of convergentinput from CT and IX and as such, these results will lead to agreater understanding of information processing in the rNTS.#P38 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsSynaptic Profile of Amygdala Terminals in RodentBrainstem Gustatory NucleiLydia N. Kullman, Robert F. LundyAnatomical Sciences and Neurobiology, School of Medicine,University of Louisville Louisville, KY, USANeurons in the central nucleus of the amygdala (CeA) sendprojections to the nucleus of the solitary tract (NST) andparabrachial nucleus (PBN) that modulate taste-elicitedresponses. However, the proportion of forebrain-inducedexcitatory and inhibitory effects appears to differ when taste cellrecording changes from the NST to the PBN. The present studyinvestigated the synaptic targets of CeA terminals in the rat NSTand PBN. Following injection of biotinylated dextran amine(BDA) into the CeA, ultra thin sections of NST and PBN tissuecontaining BDA-labeled terminals were processed for electronmicroscopy and immunogold labeled for GABA. A total of 46synapses were analyzed: n=19, NST; n=17, medial/waist PBN;and n=10, lateral PBN. The average pre-synaptic terminal areawas 0.768 + 0.079 µm 2 for NST, 0.560 + 0.059 µm 2 formedial/waist PBN, and 0.547 + 0.058 µm 2 for lateral PBN.Post-synaptic profile size was comparable between brainstemregions ranging from 1.177 + 0.290 µm 2 to 1.442 + 0.422µm 2 . Based on a threshold of 32.334 gold particles/µm 2 , themajority of CeA terminals were GABA positive (NST, 77.825 +7.357 Au/µm 2 ; medial/waist PBN, 108.676 + 9.828 Au/µm 2 ; andlateral PBN, 83.276 + 14.184 Au/µm 2 ). The post-synaptic targetsof CeA terminals were primarily non-GABAergic (NST, 13.991 +1.809 Au/µm 2 ; medial/waist PBN, 26.590 + 8.317 Au/µm 2 ; andlateral PBN, 17.433 + 8.124 Au/µm 2 ). The present results indicatethat differences in descending modulation of taste processing inNST and PBN are not due to terminals of CeA origindifferentially targeting post-synaptic GABAergic neural elements.#P39 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsActivation of the dorsal motor nucleus of the vagusnerve modulates taste responses of the neurons in theparabrachial nucleiCheng-Shu Li1 Carbondale, IL, USAThe PbN is one of the sites that integrates gustatory and visceralsensory information. It was reported that taste-responsiveneurons in the PbN were coactivated by cervical vagus nervestimulation and that taste responses of PbN neurons weremodulated by gastric distension or duodenal lipids in the rat. Thedorsal motor nucleus of the vagus nerve (DMX) is one of the areasthat visceral afferent fibers terminate. Anatomically, two types ofneurons were identified in the DMX; the cells that form efferentfibers of the vagus nerve and cells that do not. The latter type ofcells were retrogradely labeled after injection of HRP into thePbN, suggesting that part of visceral afferent information istransmitted to the PbN through the DMX. Here, we investigatedwhether taste-responsive neurons in the PbN can be coactivatedby DMX stimulation and whether activation of the DMXmodulates taste responses of the neurons in the PbN. Seventyeightof 80 PbN neurons were orthodromically activatedfollowing ipsilateral and/or contralateral DMX stimulation;38 | AChemS Abstracts 2009

75 and 39 of 80 PbN cells were activated after the ipsilateral andcontralateral DMX stimulation, respectively. Among theseactivated cells, only 7 cells were inhibited. All inhibitoryresponses were evoked after contralateral DMX stimulation.The effect of activation of the DMX on taste-driven responsesof the PN cells was examined on 20 PbN cells that were excited,and all seven cells that were inhibited after the DMX stimulation.The DMX stimulation enhanced or inhibited the taste-evokedactivities in all cells tested, parallel to the type of inputs whichthey received from the DMX. These results suggest that tasteresponsiveneurons in the PbN receive convergent input fromthe DMX and that DMX activation modulates taste responsesof these cells.#P40 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsTaste Responsive Multipolar and Elongated Neurons inHamster Nucleus of the Solitary Tract (NST) ProjectDifferentially to Targets in the Brainstem: An In-VivoIntracellular Recording, Labeling, and Tracing StudyCheng-Xiang Li 1 , Qiuhong Yang 1 , Cheng-Shu Li 2 , David V.Smith 1 , Robert S. Waters 11University of Tennessee Health Science Center Memphis, TN,USA, 2 Southern Illinois University Carbondale, IL, USANeurons in the rostral part of the nucleus of the solitary tract(NST) have been described morphologically as multipolar,elongated (fusiform), and ovoid. Attempts, including our own,to relate neuronal structure (cell size, shape, and/or dendriticconfiguration) to function (taste specific input, firingcharacteristics) have met with limited success. One avenue, stillunexplored is whether classes of NST neurons project to differenttargets in the brainstem. To address this possibility, we recordedthe activity of taste responsive neurons in NST, labeled thoseneurons with biocytin, and traced their projections to targetregions in the brainstem. We recorded responses to lingualstimulation with anodal current and to tastants that includedsucrose, NaCl, citric acid, and quinine. Recorded cells werelabeled with 2% biocytin, and the animal maintained for aminimum of 2.5 hrs to allow for axonal transport. Hamsters wereanesthetized and then perfused with saline followed by 4%paraformaldehyde. Brains were removed, sectioned at 100 µmthickness in a horizontal or sagittal plane, stained withcytochrome oxidase and/or Nissl to visualize brainstem nucleiand labeled cells. Data were taken from ten unambiguouslylabeled neurons, which were examined for taste input, firingproperties, and reconstructed using Neurolucida. Our resultssuggest that elongated cells (n=3) project exclusively to thehypoglossal nucleus while multipolar (n=7) project toparabrachial nucleus, reticular formation and/or trigeminalsensorimotor nuclei. These results obtained from a limitednumber of labeled cells suggest that NST cell morphology mayrelate, in part, to their efferent target(s).#P41 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsAnalysis of Spike Train Variability in Chemosensory NeuronsWithin the Rat Geniculate GanglionAlexandre A Nikonov 1 , Vernon Lawhern 2 , Robert J Contreras 111Department of Psychology and Program in Neuroscience, FSUTallahassee, FL, USA, 2 Department of Statistics, FSU Tallahassee,FL, USASensory neurons encode information by using the number ofspikes and /or the precise timing of these spikes. Here, weexamined the coefficient of variation (CV) of the inter-spikeinterval distribution of GG neurons after application of the basictaste stimuli. In anesthetized male rats, we recorded single-cell5-s responses from 17 narrowly tuned (8 to sucrose; 9 to MSG)and 15 broadly tuned (7 NaCl-best; 8 citric acid-best)neurons. Broadly tuned neurons responded robustly to 10 mMcitric acid and 100 mM KCl indicating input from Type III,presynaptic cells in fungiform taste buds, while narrowly tunedneurons were unresponsive to these two stimuli indicating inputfrom Type II, receptor cells. Narrowly tuned neurons had anaverage spontaneous rate of 0.3± 0.2 spikes/s, response latency of0.6 ± 0.3s, and response frequency of 8.5 ± 3.2 spikes/s. Their CVdropped gradually from 0.8 before stimulation to 0.5 after thestart of the response and remained stable thereafter during thestimulation time. Broadly tuned neurons had an averagespontaneous rate of 2.3 ± 0.6 spikes/s, a response latency of 1.5±0.7s, and response frequency of 12 ± 3.2spikes/s. Their CVdecreased from 0.9 before stimulation to an intermediate low andachieving a distinct minimum of 0.4 3-s after stimulus applicationand lasting a few hundred milliseconds. These temporal dischargepatterns were specific to some chemical stimuli or mixtures ofthem. Analysis of patterns of activity across many neurons willhelp us understand how GG neurons code taste information.#P42 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsNeuron Survival and Central Terminal Field PersistenceDespite Limited Peripherial Regeneration of the InjuredChorda Tympani Nerve in Adult RatsRebecca Reddaway, David L. HillUniversity of Virginia Charlottesville, VA, USAUnilateral chorda tympani nerve transection (CTX) producespersistent morphological and physiological changes in theperipheral and central taste systems despite functionalregeneration of the injured nerve in adult rats. To betterunderstand changes resulting from CTX, we focused experimentson the injured CT nerve. Primary sensory neuron death andtransganglionic degeneration are typical consequences of sensorynerve transection and are often attributed to the loss of trophicsupport from peripheral target organs. However in the tastesystem where the peripheral targets (taste buds) are constantlyturning-over, there is potential for an attenuated peripheraltrophic dependence. The current study uses fluorescent retrogradetracers to measure CT cell numbers in the geniculate ganglia andnerve terminal field volumes in the rostral nucleus of the solitarytract (rNTS) following nerve injury. Two different fluorescentlabels, the first (DiI) applied at the time of CTX and the second(Micro-Emerald) at 14, 60, 90, or 120 post-CTX, were used tomeasure 1) the total number of CT neurons surviving CTXP O S T E R SAbstracts | 39

and 2) the number of CT neurons with regenerated peripheralaxons. Transgangionically transported fluorescent label allows usto compare the volume of vestigial and functional CT nerveterminal field post-CTX. Our results indicate that CT cells do notdie following CTX, despite attenuated regeneration of peripheralaxons. In addition, measures of labeled CT terminal fields in therNTS indicate 1) a lack of degeneration, and 2) a reduction incentral axons that are functionally connected to peripheraltargets. Such measures will be useful for understanding injuryinducedchanges seen in experimental animal populations andtaste abnormalities seen in human patients after CT nerve injury.#P43 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsA Network Model of Taste Processing in the Nucleus of theSolitary TractA.M. Rosen 1 , H. Sichtig 2 , J.D. Schaffer 2,3 , P.M. Di Lorenzo 11Dept. of Psychology, Binghamton University Binghamton, NY,USA, 2 Dept. of Bioengineering, Binghamton UniversityBinghamton, NY, USA, 3 Philips Research, North Am.Briarcliff Manor, NY, USAThough the functional architecture of many primary sensorynuclei has been well characterized, the organization of the nucleusof the solitary tract (NTS), the first central relay for gustation,remains a mystery. Here, we used electrophysiological datarecorded from single cells in the NTS to inform a network modelof taste processing. Previous studies have revealed that stimulationof the chorda tympani (CT) nerve initiates two forms ofinhibitory influences in separate groups of NTS cells. These formsof inhibition differed in time course and were correlated withdistinct NTS taste response properties. That is, one inhibitoryinfluence peaked early, decayed rapidly and was associated withshort latency responses to CT stimulation and narrow tuningacross tastants. Conversely, the second inhibitory influencepeaked late, decayed slowly and was seen in cells with longlatency responses to CT stimulation and broad tuning. Based onthese data, we designed a model of the NTS consisting of discretecell assemblies with a projection neuron and two different typesof inhibitory interneuron. Each cell assembly is reciprocallyconnected to every other and is characterized by a distinct profileof sensitivity across tastants. Input to the network of integrateand-firemodel neurons was based on recordings from the CTnerve. Responses to taste stimulation as well as paired-pulse CTstimulation were simulated. The network dynamics of the NTSmodel operated in a “winner-take-all” fashion, where differencesin the stimulus sensitivities between assemblies enhanceddiscrimination between taste qualities. We propose that suchdynamics may account for the coherence in across neuronpatterns of NTS responses between similar tastants.#P44 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsLinoleic acid does not enhance chorda tympani nerveresponses to sucrose, citric acid and quinine hydrochlorideJennifer M Stratford, Robert J ContrerasFlorida State University Department of Psychology and Programin Neuroscience Tallahassee, FL, USAPrevious studies suggest that the chorda tympani nerve (CT) isimportant in carrying fat taste information to the central nervoussystem, as bilateral transection of the CT (CTX) raises the tastediscrimination threshold for the free fatty acid, linoleic acid (LA).Surprisingly, the CT is unresponsive to lingual application of LAalone. However, electrophysiological studies of isolated tastereceptors have shown that LA inhibits delayed rectifyingpotassium channels, presumably broadening action potentials,and augmenting responses to other taste stimuli (Gilbertson et al,1997). Thus, the contribution of the CT in this process maydepend upon the presence of other taste stimuli. In this regard,we previously found that co- application of LA and eithermonosodium glutamate (MSG) or sodium chloride (NaCl)elicited greater CT responses than did either MSG or NaClpresented alone (Stratford et al, 2008). In the present study, werecorded CT electrophysiological activity in response to tastemixtures of LA and sucrose (SUC), citric acid (CA), or quininehydrochloride (QHCl) in anesthetized male rats. Unlike theeffects observed with MSG and NaCl, we found that the additionof LA did not alter CT responses to SUC, CA and QHCl.However, CT is weakly responsive to SUC, CA and QHCl inrats. Therefore, CT whole nerve recordings may lack thesensitivity to detect small changes in CT responses to these tastestimuli. It is more probable, however, that LA may affect CTresponses to MSG and NaCl only, perhaps by specificallymodulating gustatory processing of Na+- which is found in bothMSG and NaCl. This possibility may be explored in futurestudies using a pharmacological antagonist of epithelial sodiumchannels or a non sodium salt, such as potassium chloride.#P45 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsImprovement of olfactory function in patients treatedfor chronic rhinosinositis is related to increasing olfactorybulb volumeVolker Gudziol, Dorothee BuschhüterSmell and Taste Centre Dresden, GermanyAim of the present study was to investigate whether the humanolfactory bulb (OB) volume increases after short-term treatmentof olfactory function. Nineteen patients with chronicrhinosinositis with polyps were investigated. All patients receivedfunctional endoscopic sinus surgery. In addition, 18 volunteerswithout history and endoscopic signs of chronic rhinosinositiswere also investigated. Measurements were performed on 2occasions separated by 3 months in patients and 4 month incontrols. Olfactory function was evaluated in great detailseparately for each nostril; MR scans of the OB wereperformed. Volumetric measures of the OB were based onplanimetric manual contouring. In healthy controls the OBvolume was not significantly different between the twomeasurements. In contrast, OB volume in patients increasedsignificantly from initial 64.5 ± 13.9mm³ to 70.0 ± 15.3mm³40 | AChemS Abstracts 2009

on the left side and from 60.9 ± 15.5mm³ to 72.4 ± 12.4mm³ onthe right side. Change of odor thresholds correlated significantlywith the change of OB volume. However, changes in odordiscrimination and identification did not show such a significantcorrelation. Results of this study support the idea that olfactorystimulation of olfactory receptor neurons impacts on the celldeath in the OB not only in rodents but also in humans. To ourknowledge this is the first study that describes an enlargement ofthe human OB due to improvement of peripheral olfactoryfunction.#P46 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsTerminal Field Organization of the Chorda Tympani, GreaterSuperficial Petrosal, and Glossopharyngeal Nerves in Nucleusof the Solitary Tract in C57BL/6J MiceChengsan Sun, David HillUniversity of Virginia Charlottesville, VA, USAThe nucleus of the solitary tract (NST) is the first central relay inthe gustatory system, receiving information originating fromdiscrete receptor populations in the oral cavity through multiplenerves. Three of the nerves carrying taste information havedistinct and partially overlapping terminal fields in the adult ratNST. The development of each field is unique and each isdifferentially susceptible to early dietary manipulations.Therefore, the primary afferent terminal fields in rat are“plastic” during normal and experimentally altered development.To complement these findings, we have begun to characterize theterminal field organization in adult mice that are often used as thebackground strain for genetic manipulations. Through the use oftriple-fluorescence labeling and confocal laser microscopy,terminal fields of the greater superficial petrosal (GSP), chordatympani (CT), and glossopharyngeal (IX) nerves were visualizedconcurrently in horizontal sections of the NST in adult C57BL/6Jmice (> 60 days old). The terminal fields overlapped extensivelywith each other, with the IX terminal field located slightlymore dorsally than the CT and GSP. The CT terminal field waspositioned slightly more lateral than the GSP; however, there wassignificant overlap between them from their dorsal to ventralextent. Compared to rat, the terminal fields in mice overlappedsignificantly more with a different topography. These findingswill be fundamental in designing studies that focus on theunderlying cellular and molecular mechanisms responsible forterminal field development and plasticity. Supported by NIHgrant R01 DC00407.#P47 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsCharacteristics of convergent synaptic activity between thecaudal brainstem gustatory nucleus and neurons in the chordatympani terminal field projecting to the parabrachial nucleusTakeshi Suwabe, Robert M. BradleyDepartment of Biologic and Materials Sciences, School ofDentistry, University of Michigan Ann Arbor, MI, USAThe rostral nucleus of the solitary tract (rNST) is the first rely inthe central taste pathway. The rNST distributes gustatoryinformation derived from stimulating oral structures to eitherbrainstem motor nuclei or to more rostral brain regions.We have focused on the rostrally projecting rNST neurons to theparabrachial nucleus (PBN) identified by retrograde labeling withan iontophoretic injection of DiI into the PBN. Anatomical andin vivo electrophysiological studies have reported intra-rNSTconnection in the rostrocaudal direction suggesting convergenceof chemosensory information from anterior and posterior oralreceptive fields. The purpose of this study was to characterize thisconvergence between the glossopharyngeal (IX) terminal field andthe PBN-projection neurons located in the chorda tympani (CT)terminal field. We recorded postsynaptic currents (PSC) fromPBN-projection neurons in the rostralmost rNST in rat brainstemslices at postnatal ages of 50-60 days. PSCs were evoked byelectrical stimulations of the solitary tract in the IX nerve terminalfield. Two groups of PSCs were recorded (24 postsynaptic eventsfrom 12 neurons). The first group had a long latency with jitter(standard deviation of mean latency) values that exceeded 200 sand had very variable PSC amplitude. The second group had shortlatencies with low jitter values and constant PSC amplitudes. Theresults indicate that individual rNST PBN-projection neurons inthe CT terminal field receive convergent IX afferent input viaboth monosynaptic and polysynaptic connections. Supported byNIDCD grant DC000288 to RMB.#P48 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsA Murine Model for Induced Allergic RhinitisVirginia McM. Carr, Alan M. Robinson, Robert C. KernDept. of Otolaryngology, Feinberg School of Medicine,Northwestern University Chicago, IL, USAThe aim of this study was to develop a murine model forinduction of allergic rhinitis (AR) so as to enable future studiesof AR effects on olfactory mucosa, olfactory functionalcapabilities, and effects of pharmacological treatments thereupon.We report results using a modification of the localized asthmainduction protocol of McCusker et al. (J.Allergy Clin.Immunol.110:891, 2002). Balb/C mice were subjected to bilateralnasal infusions of 7.5µl/naris of filter-sterilized (0.2µm pore size)ovalbumin (OVA; 1% in PBS) or PBS. Chronic treatmentinvolved infusions made M-F for 6 or 11 wks, with definedbreaks in the regimen to enhance allergic response intensity.Acutely treated mice were sacrificed one day after single bilateralinfusions. Untreated animals served as controls. Mice were deeplyanesthetized and perfused with 4% PFA following cardiac bloodcollection. Paraplast serial sections through the nasal cavities wereexamined for overall histology of nasal epithelia, presence anddistribution of eosinophils, and distribution of OMP and NT-IIIimmunoreactivies. Results indicate that significant allergenicresponses occurred in all chronically OVA-treated animals: serumELISAs show large OVA-specific IgE increases and laminapropria eosinophil numbers were strikingly increased immediatelysubjacent to the RE and to a lesser extent deep to the OE. The OEshowed noticeable disruption, especially at 11 wks, includingOSN loss, Bowman’s gland OE intrusion, and lamina proprianeuroma formation. Significant RE cellular edema also occurred.None of these changes was seen in acute PBS or OVA, chronicPBS, or untreated animals. Examination of OSN turnover isplanned.P O S T E R SAbstracts | 41

#P49 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsObjective evaluation of the impact of chronic rhinosinusitis(CRS) on olfactory functionKai Zhao 1,2 , Edmund A. Pribitkin 1,2 , Nancy E. Rawson 1,3 ,David Rosen 2 , Christopher T. Klock 1 , Aldona A. Vainius 1 ,Pamela Dalton 1 , Beverly J. Cowart 1,21Monell Chemical Senses Center Philadelphia, PA, USA,2Otolaryngology, Head & Neck Surgery, Thomas JeffersonUniversity Philadelphia, PA, USA, 3 WellGen, Inc. NorthBrunswick, NJ, USAChronic rhinosinusitis (CRS) is both one of the most commonchronic diseases in the U.S., afflicting over 30 million adults, andone of the most common causes of smell loss. Yet, not all sufferersof CRS experience smell problems. In order to develop targetedtherapies for this form of smell loss, it is critical that we identifyeffective tools to evaluate the functional impact of the diseaseprocess on the olfactory system. To this end, the Monell-JeffersonChemosensory Clinical Research Center has enrolled 55 patientswith clearly defined CRS and performed a battery of objectiveassessments on them, including acoustic rhinometry,rhinomanometry, CT scans and nasal endoscopic evaluations,with each tool indexing different aspects of disease status.Rhinometry primarily reflects the airway cross-sectional area andresistance contributed by the anterior portion of the nasal cavity,endoscopy evaluates the main nasal airway, ostiomeatal complexand olfactory cleft, whereas CT staging scores weight heavily onthe surrounding sinuses. Our findings indicate that none of thesetools by themselves discriminate degrees of olfactory loss due toCRS. Endoscopy scores and CT scores of the ethmoid sinuses areexcellent indices for the most severe olfactory loss, anosmia, yetfail to differentiate hyposmic patients from those with noolfactory loss. The minimum cross sectional area (MCA)measured by acoustic rhinometry correlates significantly withunilateral olfactory thresholds of patients, but only for the highsoluble odorant l-carvone, not for the low soluble d-limonene,which may reflect a conductive mechanism. In the future,carefully weighted combinations of multiple objective tools mayprovide a better evaluation of the aspects of this disease processthat impact olfactory function.#P50 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsPalinosmia: Olfactory PerseverationAlan R HirschSmell & Taste Treatment and Research Foundation Chicago, IL,USASensory perseveration occurs in the auditory (Palinacousis),somesthetic (Palinesthesia), and visual (Palinopsia) spheres.Olfactory perseveration (Palinosmia) has not been described.Four cases are presented. Case 1: 64 year-old male with upperrespiratory infection, followed by a smokey, burnt woodphantosmia. Smelling or eating replaced the phantosmia with theambient or retronasal odor which would persist four hours afterinhalation or consumption. Fiberoptic endoscopy, MRI of brain,and sinus CT were negative. UPSIT (27/R, 20/L), PEA Threshold(>-2.0/R, –5.0/L). Case 2: 38 year-old female, 19 years prior,sustained a traumatic subdural hematoma and coincident anosmiawith monthly phantosmias of smoke or fish. Three months priorto presentation, she developed a prolongation of perception ofsmell, even after removed from the vicinity of the odor. UPSIT(24/R, 28/L). Case 3: 32 year-old woman fell off a horse withfrontal contusion and basal skull fracture, anosmia and anintermittent unpleasant chemical smell which was precipitated byexposure to strong odors, persisting for days after the ambientodor stimulus had been removed. PEA (> –2.0/R, >-2.0/L) andUPSIT (11/R, 7/L). Case 4: 48 year-old woman with upperrespiratory infection-induced anosmia replaced by a “foul, rottenfish” odor in response to any smells or tastes which persisted forhours after the stimulus odor. Fiberoptic endoscopy, CT ofsinuses, and MRI of brain were negative, UPSIT (20/R, 18/L),PEA (-4.5/R, -2.0/L). CONCLUSION: Unlikephantosmia,Palinosmia may be viewed as the abnormalperseveration of a true or distorted olfactory stimulus.#P51 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsBimodal odorant perception in anosmic subject: a fMRi studyEmilia Iannilli 1 , Thomas Bitter 2 , Hilmar Gudziol 2 ,Hartmut Burmeister 3 , Anita Chopra 41Dept. of ORL, University of Dresden Medical School Dresden,Germany, 2 Dept. of ORL, University of Jena Jena, Germany,3Dept. of Radiology, University of Jena Jena, Germany, 4 UnileverR&D Port Sunlight Birmingham, United KingdomMost odorous compounds stimulate both olfactory and intranasaltrigeminal receptors.It is not entirely clear which brain areasspecifically relate to within each system and those common toboth systems. In order to further investigate the cross-interactionbetween the two systems, a block design functional magneticresonance (fMRI) study was set up. For stimulation we chose thebimodal stimulus menthol was presented in two differentconcentrations to two groups of subjects, an healthy controlgroup and an anosmic group (no sense of smell) (17 subjects ineach group). For stimulus presentation computer-controlled airdilutionolfactometer was used. Image acquisition was performedby means of 3T MRI-scanner (Siemens Magnetom Trio TimSystem 3T; TR 2s; TE 30ms; FA 90°; 1.72x1.72x2 mm). SPM5 wasused for data analysis. Normosmic subjects exhibited activation inthe anterior and posterior cingulate cortex, prefrontal cortex, andcerebellum. On the other side, anosmic patients activated the samearea inside the anterior cingulate; moreover a cluster of activationwas found in the left parahippocampal gyrus. In controls, an effectof stimulus intensity was localized between the anterior cingulateand the medial frontal gyrus; such areas could not be found inanosmic subjects. Among others these results clearly indicate thatthe olfactory system seems to amplify trigeminally mediatedinformation resulting resulting in more efficient informationprocessing related to differentiation between stimulus intensities.42 | AChemS Abstracts 2009

#P52 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyThe Nutritional Significance of Oral Starch DigestionAbigail L. Mandel, Kimberly L. Plank, Paul A.S. BreslinMonell Chemical Senses Center Philadelphia, PA, USAThe digestion of starches is accomplished by salivary andpancreatic a-amylases, endo-enzymes that catalyze the hydrolysisof a-1,4 glycosidic linkages to produce maltose, maltotriose andlarger oligosaccharides. Salivary amylase initiates the digestion ofstarch in the oral cavity, producing a rapid decrease in glucosepolymer chain length and viscosity with the cleavage of relativelyfew glycosidic bonds. Amylase is the most abundant protein inhuman saliva, with a significant amount of variation amongindividuals. However, the selective advantage provided by thebreakdown of starch in the oral cavity has never been established,since the majority of ingested starch is digested in the smallintestine by pancreatic amylase. Accordingly, the nutritionalsignificance of oral amylase production is unknown. We posit thatthe presence of salivary amylase facilitates a more efficient andcomplete breakdown of ingested starch than does pancreaticamylase alone. We address this question by examining how thepre-ingestive breakdown of starch by salivary amylase affectsabsorption of glucose in the small intestine. Furthermore,individuals who produce more salivary amylase may have fasterand larger postprandial blood glucose responses. This question isaddressed by measuring changes in blood glucose levels followingstarch ingestion and quantifying salivary amylase levels andenzymatic activity. The results of this work will help elucidate thenutritional consequences of the production of high salivaryamylase levels.#P53 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyCharacterization of Off-odor development in human milkduring storage at -18 °CJohanna Spitzer 1 , Andrea Buettner 1,21Institute of Pharmacy and Food Chemistry, Department FoodChemistry, University Erlangen-Nürnberg 91052 Erlangen,Germany, 2 Fraunhofer Institute for Process Engineering andPackaging (IVV), Giggenhauser Str. 35, D-85354 Freising,GermanyObjectives. Human milk has been reported to be storable at -18 °C for a maximum of 3 to 6 months, and at +4 °C for 3 to 8weeks. Subsequent recommendations on storage have been basedon stabilities of beneficial milk constituents, as well as on hygieneconsiderations [1]. However, sensory changes of human milkduring storage have hitherto not been investigated. Since chemosensoryaspects of human milk have been shown to be ofenormous importance for the neonate [2], this study aimed atcharacterizing potential flavor changes in human milk duringstorage. Experimental. Changes in ortho and retronasal flavorprofiles of fresh human milk in comparison to those stored at -18 °C were monitored by descriptive sensory evaluation.Furthermore, identification of predominant odor substances wasaccomplished by senso-analytical techniques such as gaschromatography-olfactometry/massspectrometry (GC-O/MS),comparative dilution assay (cAEDA), and stable isotope dilutionassays for quantification of major flavor changes. Results. Sensoryevaluation of the ortho and retronasal flavor attributes of freshand stored human milk indicated dramatic differences, mostspecifically with the formation of fishy, rancid, metallic andcooked-milk-like aroma impressions in the stored samples.The chemo-analytical methodology was successfully applied foridentification of more than forty odorants in fresh and storedhuman milk, and allowed for molecular characterization of thekey odor modifiers of the fresh milk smell. Conclusions.Conventional storage led to major flavor changes of human milkand should be reconsidered on the basis of the sensory andchemo-analytical data presented here. References. [1] PardouA et al. Biol Neonate 65:302 to 309, 1994. [2] Soussignan R et al.Physiol Behav 1997, 62, 745-758.#P54 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyChronic otitis media is associated with a marker of tastedamage and higher weight status in childrenAlison K. Ventura, Danielle R. Reed, Julie A. MennellaMonell Chemical Senses Center Philadelphia, PA, USAOtitis media (OM) is the most common illness of young children.Because the chorda tympani nerve passes through the middle ear,it may be particularly vulnerable to OM. Consequently, tasteperception and food habits may be altered due to the damage orother unknown factors associated with OM. In support of thishypothesis, Bartoshuk and colleagues report that adults withmore severe histories of OM prefer diets higher in sugar and fatand have higher BMIs. In the present study, we obtainedretrospective reports of OM history from the mothers of 227children (age 3 to 10 years). Mothers were also queried about theirsmoking habits and children’s feeding histories. Children weremeasured and weighed, genotyped for the TAS2R38 gene, andphenotyped for propylthiouracil (PROP) sensitivity and sucrosepreferences. Irrespective of genotype, children who reported the560µmol/L PROP solution tasted metallic (“like a penny”), anindication of taste nerve damage, had experienced more episodesof OM than children who did not report a metallic taste (P

#P55 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyFood Liking, Ear Infections and Body Mass Index AmongPreschoolersKerah Kennedy 1 , Heather L. Harrington 1 , Stephanie Scarmo 2 ,Valerie B. Duffy 11Allied Health Sciences, Univ of CT Storrs, CT, USA,2Public Health, Yale Univ New Haven, CT, USANational overweight rates among preschoolers have grown from5% in 1976 to 13.9% in 2004. Otitis media (OM) history has beenlinked to children’s overweight risk from a small study (Tanasescuet al, 2000) and nationally-representative longitudinal study(Hoffman et al, 2006). We examined OM history and dietarybehaviors associated with overweight risk among 485preschoolers (248 males, mean age=45±7 months) in two urbanpreschool centers. Most of the preschoolers were Black (27%) orHispanic (56%). From measured weight/height and age/genderspecificBMI percentiles, 4% were underweight, 21% hadoverweight risk (85-95th) and 21% were overweight (≥95th).From parent-completed surveys, 70% had OM at least once and31% were food neophobic. Sweet, salty or high-fatfoods/beverages were liked most while vegetables were liked least.In analysis of variance, controlling for demographic variables(ANCOVA), food neophobic preschoolers had less liking for avegetable/fruit group than did non-neophobic preschoolers(p

#P58 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyBitesize is affected by Food Aroma presented at Sub- orPeri Threshold ConcentrationsRene A de Wijk 1 , Ilse A. Polet 1,2 , Johannes HF Bult 2,31AFSG/CICS Wageningen, Netherlands, 2 TIFN Wageningen,Netherlands, 3 NIZO Food Research Wageningen, NetherlandsBite sizes for foods typically vary with the food’s familiarity andwith its hedonic and textural properties. More over, smaller bitesizes tend to be more satiating than larger ones and bite sizes tendto become smaller when the consumer becomes more satiated.These results indicate that bite size control is sensitive to generalfood properties as well as to the internal state of the consumer.To explore the effect of food aromas on bite size, a semi-solidvanilla custard dessert was delivered into the mouth of subjectsusing a pump while a cream aroma was presented retro-nasally inthe nose. Termination of the pump, which determined bite size,was controlled by the subjects via a pushbutton. Over 30 trials thecustard was presented randomly either without an aroma, or witharomas presented below or near detection threshold. Results for10 subjects, 4 females and 6 males aged between 26 and 50 years,indicated that aroma intensities affected sizes of the correspondingbites as well as subsequent bites. Higher aroma intensities resultedin significantly smaller sizes of the corresponding bite. Higheraroma intensities resulted in a directional similar but smaller andnon-significant effect on the subsequent bite, and a reversed andsignificant effect on the bite thereafter. These results suggest thatbite size control during eating is a highly dynamical processaffected by sensations elicited by present and preceding bites.The results contribute to our understanding of bite-size andfood intake regulations, and may be of relevance for weightmanagement.#P59 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologySimilarities in Food Cravings and Mood States betweenObese Women and Women who Smoke TobaccoSusana Finkbeiner 1 , M. Yanina Pepino 1,2 , Julie A. Mennella 11Monell Chemical Senses Center Philadelphia, PA, USA,2Washington University, School of Medicine St. Louis, MO, USAWomen who smoke crave starches and fats more frequently thanthose who never smoked. Here, we determined whether thesecravings and some mood disturbances were related to effects ofsmoking per se or were characteristic of women who were likelyto smoke. Further, because obese individuals crave fats morefrequently than lean counterparts, we explored whether theseassociations were affected by body weight. We interviewed andgrouped 229 women according to smoking history (neversmokers, former smokers and current smokers) and body weightcategory (normal weight, overweight, obese). Each subjectcompleted the Food Craving Inventory to measure cravings forsweets, high fats, starches, and fast food fats and the Profile ofMood States to measure psychological distress. We found that,even after controlling for socioeconomic factors, smoking andobesity were independently associated with specific food cravingsand mood states. Current smokers craved fats more frequentlythan former and never smokers. They also craved starches morefrequently, and felt more depressed and angrier, than neversmokers, but not former smokers. Similarly, obese women cravedfats more frequently than non obese women and depressionsymptoms were intensified with increasing body weights. Inconclusion, whereas cravings for starchy foods and some moodstates may be characteristic of women who are likely to smoke,more frequent cravings for fat is probable an effect of smoking perse. We hypothesize that the overlapping neuroendocrinealterations associated with obesity and smoking and theremarkable similarities in food cravings and mood states betweenwomen who smoke and women who are obese suggest thatcommon biological mechanisms modulate cravings for fat in thesewomen.#P60 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyPROP Sensitivity and Dietary Intake ofAntioxidant-Rich FoodsYvonne Koelliker 1 , Beverly J. Tepper 1 , James E. Simon 2 , John R.Burgess 31Dept. of Food Science, Rutgers University New Brunswick, NJ,USA, 2 Plant Biology and Pathology, Rutgers University NewBrunswick, NJ, USA, 3 Dept. of Foods and Nutrition, PurdueUniversity West Lafayette, IN, USAAntioxidant-rich foods are known to be an important part of ahealthy diet. However, often these foods can have high levels ofphytonutrients which impart a bitter taste, making them lessacceptable to consumers. Genetic sensitivity to 6-npropylthiouracil(PROP) may be a marker for the selection ofantioxidant-rich foods. Some studies have demonstrated thatPROP non-tasters (NT) showed a higher acceptance of bitterfruits and vegetables (sources of Vitamins A, C, and E) andvegetable oils (source of Vitamin E) than medium (MT) andsuper-tasters (ST). The aim of this study was to relate PROPsensitivity to the dietary intake of these major antioxidantvitamins. Healthy, non-vegetarian females, ages 21-44 yrs, whodid not take dietary supplements were classified as NT (n=30),MT (n=33), and ST (n=30) based on the PROP paper diskmethod. The subjects provided three, 24-hour diet recalls whichwere collected and analyzed using NDS-R software. Eatingattitudes were measured using the Dutch Eating BehaviorQuestionnaire. There were no differences in the consumption offruits, vegetables, or vegetable oils across taster groups. However,when the subjects were further divided by restrained eating,NT who were also low in dietary restraint had higher intakes ofa-tocopherol (Vitamin E) than the other groups (p=0.05). Thesedata are consistent with Tepper et al, 2008, showing that NT hadhigher plasma a-tocopherol levels than MT and ST. Takentogether, these data suggest that NT consume more a-tocopherol(principally derived from green vegetables and vegetable oils inthe U.S. diet), which may be reflected in higher plasma indices forthis antioxidant nutrient. The health implications of thisrelationship should be further examined.P O S T E R SAbstracts | 45

#P61 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyAssociation of a TAS2R38 Polymorphism and the EatingBehavior Disinhibition in a Female Amish CohortCedrick D. Dotson 1 , Hillary Shaw 2 , Steven D. Munger 1 ,Nanette I. Steinle 21Department of Anatomy & Neurobiology, University ofMaryland School of Medicine Baltimore, MD, USA, 2 Departmentof Medicine, Division of Endocrinology, Diabetes and Nutrition,University of Maryland School of Medicine Baltimore, MD, USAInsensitivity to the bitter-tasting compound 6-n-propylthiouracil(PROP) has been associated with increased adiposity, especiallyin women. The principal genetic determinants of phenotypicvariation in PROP taste sensitivity are haplotypes of the TAS2R38gene, which encodes a taste receptor sensitive to thioureacompounds such as PROP and phenylthiocarbamide. As dietaryintake can affect adiposity, we asked if variation in TAS2R38 isassociated with any of 3 eating behaviors: restraint (a cognitiveavoidance of eating to control body weight), disinhibition (a lossof restraint associated with overeating), and hunger. We hadpreviously genotyped haplotype-tagging, single nucleotidepolymorphisms (SNPs) located within the TAS2R gene cluster onhuman chromosome 7 (which includes TAS2R38) in 729nondiabetic individuals (381 females, 348 males) within the AmishFamily Diabetes Study. Eating behaviors were assessed in theseindividuals using the Three-Factor Eating Questionnaire. Weperformed association analysis of the TAS2R38 SNP rs1726866and these three traits. Results of our analysis (adjusted for age andsex) showed a marginally significant association of the minor (C)allele with decreased disinhibition (P=0.03). Stratification of thecohort by sex revealed a strong association in females (P=0.0002)but not in males (P=0.76). Analyses with other haplotype-taggingSNPs in close proximity to rs1726866 suggest that this locus isprincipally responsible for the association signal. Therefore, ourresults indicate that a polymorphism in TAS2R38 is associatedwith differences in ingestive behavior. Support: DC005786,HL076768, DK072488, DE007309, UMSOM.#P62 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyModulation of sweet taste sensitivity by glucagon signalingin taste budsAmanda E.T. Elson 1 , Cedrick D. Dotson 1 , Josephine M. Egan 2 ,Steven D. Munger 11Department of Anatomy and Neurobiology, University ofMaryland School of Medicine Baltimore, MD, USA, 2 NationalInstitute on Aging/NIH Baltimore, MD, USAHormones that facilitate glucose homeostasis in the gut may alsoregulate taste sensitivity in taste buds. For example, glucagon-likepeptide 1 (GLP-1), a regulator of insulin biosynthesis and release,is expressed in taste receptor cells and appears to modulate sweettaste sensitivity through local paracrine signaling. We previouslyshowed that glucagon is expressed in a subset of taste receptorcells, but its pattern of distribution and effects on taste functionare not known. We quantified the expression of glucagon, itsreceptor (GlucR) and other taste cell markers in mousecircumvallate taste buds using immunohistochemistry andstereological cell counting. In contrast to GLP-1, which isexpressed in subsets of both 5HT+ and PLC 2+ cells, glucagonimmunoreactivity is largely restricted to a subset of PLC 2+ cells.We saw similar expression patterns in fungiform and foliate tastebuds. GlucR expression appears to overlap with that of glucagon,suggesting an autocrine signaling mechanism in taste buds.We next tested the effects of a highly-specific GlucR antagonistL-168,049 using a brief access taste test. Mice that received thedrug showed a significant reduction in taste sensitivity to sucrose;there were no significant differences in responses to NaCl ordenatonium benzoate. Together, these data suggest a role forglucagon signaling at the level of the taste bud in the modulationof sweet taste sensitivity.#P63 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologySweet receptor gene (Tas1r2) structure and preference forsweet stimuli in species of CarnivoraJoseph G. Brand 1,3 , Dieter Glaser 2 , Weihua Li 1 , Gary K.Beauchamp 1,4 , Xia Li 11Monell Chemical Senses Center Philadelphia, PA, USA,2Anthropological Institute and Museum, University of ZürichZürich, Switzerland, 3 Department of Biochemistry, School ofDental Medicine, University of Pennsylvania Philadelphia, PA,USA, 4 Department of Psychology, School of Arts and Sciences andDepartment of Anatomy, School of Veterinary Medicine,University of Pennsylvania Philadelphia, PA, USAThe extent to which taste receptor specificity correlates with, oreven predicts, diet choice is not known. We recently reported thatthe insensitivity to sweeteners shown by species of Felidae can beexplained by the observation that the gene for their sweet tastereceptor is a pseudogene. To broaden our understanding of therelationship between the structure of the sweet receptors andpreference for sugars and artificial sweeteners, we measured tasteresponses to 12 sweeteners in select species of Carnivora usingtwo-bowl preference tests, and sequenced the Tas1r2 gene in thesesame (or closely related) species using PCR. Based on behavioraland molecular data, we found that lions showed no preference forany of the 12 sweet compounds tested and that they possess thepseudogene of Tas1r2. All other species tested preferred some ofthe natural sugars, and their Tas1r2 sequences, having completeopen reading frames, predict functional sweet receptors. Onespecies, the lesser panda, in addition to preferring natural sugars,also preferred three (neotame, sucralose and aspartame) of the sixartificial sweeteners. Heretofore it had been reported that amongvertebrates, only Old World simians could taste aspartame. Thesedata suggest an evolutionary convergence or a serendipitousmutation in the sweet receptor of the lesser panda. Continuingstudies will provide insights into the nature and function of tastereceptor genes and how their variation affects taste perception,food choice and nutritional status.46 | AChemS Abstracts 2009

#P64 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyGABA-A Receptor Activation Influences Consumptionof Appetitive and Aversive TastantsDavid W. Pittman 1 , Molly McGinnis 1 , Elizabeth Miller 1 ,Lindsey Richardson 1 , John-Paul Baird 21Department of Psychology, Wofford College Spartanburg, SC,USA, 2 Department of Psychology, Amherst College Amherst,MA, USABenzodiazepines act through GABA-A receptors to increase theinhibitory effect of GABA in the brain. Previous research hasshown that hyperphagia is a common side effect ofchlordiazepoxide (CDP) and benzodiazepines in general.Although the majority of previous research has focused primarilyon the palatability of sweet stimuli, a taste reactivity test suggestedthat benzodiazepines influence appetitive responses with little orno effect on responses to sour or bitter taste stimuli. The objectiveof this study was to examine the effects of CDP on lickingresponses to not only appetitive stimuli but also aversive stimuliacross a range of concentrations. Using counterbalancedmethodology, a within-subject design assessed the effect of CDP(10mg/kg) versus saline on the microstructural licking patterns ofwater-restricted rats (n=16) to one concentration of saccharin,sucrose, NaCl, MSG, citric acid, or quinine (Q-HCl) during 1-hrtests. Licking responses across 3 concentrations of each tastantwere compared using a between-subject analysis. Results from thepresent study show that CDP increased the appetitive qualitiesacross all of the taste categories, primarily through changes intaste-mediated variables. CDP increased the number of meal licks(sucrose, saccharin, MSG, NaCl, Q-HCl) through shorter pausedurations (sucrose, saccharin, MSG, NaCl, citric acid), increasedlick rates (sucrose, saccharin, MSG, Q-HCl, citric acid), andincreased licks in the first minute of testing (saccharin, NaCl,citric acid, Q-HCl). There was no drug effect on variablesassociated with post-ingestive feedback such as meal duration ornumber of bursts. This supports previous research thatbenzodiazepines enhance the taste palatability of sweet stimuliand expands this finding to umami, salt, and bitter tastants.#P65 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyConditioned preferences for glucose and fructose inT1R3 KO and TRPM5 KO miceSteven Zukerman 1 , Robert F. Margoskee 2 , Anthony Sclafani 11Brooklyn College of CUNY Brooklyn, NY, USA, 2 Mount SinaiSchool of Medicine New York, NY, USADeletion of the genes for the sweet taste receptor subunit T1R3or the signaling protein Trpm5 greatly attenuates sweetenerpreference in mice. However, knockout (KO) mice missing T1R3or Trpm5 develop preferences for sucrose solutions in 24-h testsdue to the post-oral actions of the sugar. The present studycompared the preferences of KO and C57BL/6J wildtype (WT)mice for glucose and fructose in 24-h taste tests with 0.5-32%sugar vs. water. Unlike glucose and sucrose, fructose has minimalpost-oral reward effects. T1R3 KO mice were initially indifferentto dilute glucose solutions (0.5-4%) but developed preferences for8-32% sugar in test 1. They strongly preferred (~90%) all glucoseconcentrations in test 2. New T1R3 KO mice were indifferent to0.5-8% fructose but avoided 16-32% fructose in both tests.Trpm5 KO mice were indifferent to 0.5-4% glucose but preferred8-32% glucose in test 1 and all concentrations in test 2. NewTrpm5 KO mice were indifferent to 0.5-32% fructose in test 1 butmildly preferred (~75%) fructose in test 2. WT mice preferredglucose and fructose in both tests. Why T1R3 KO but not Trpm5KO mice avoided 16-32% fructose is uncertain. Perhaps fructoseabsorption is impaired in T1R3 KO mice (due to missing gutT1R3 receptors) which inhibits fructose intake. Yet T1R3 KO andTrpm5 KO mice given glucose in tests 1 and 2 subsequentlydisplayed strong (~90%) preferences for 0.5%-32% fructose in athird test. Apparently, the post-oral effects of glucose condition astrong preference for the sugar’s T1R3-independent orosensoryproperties (odor, texture) that generalize to those of fructose.Fructose, rather than glucose or sucrose, can be used with tasteimpairedKO mice to evaluate 24-h sugar taste preferences withpost-oral reward effects minimized.#P66 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyNutrient-specific preferences in trpm5 knockout miceXueying Ren 1,2 , Jozelia G Ferreira 1,2,3 , Jenny Tong 4 ,Catherine W Yeckel 1,5 , Ivan E de Araujo 1,21The John B Pierce Laboratory / Yale University New Haven,CT, USA, 2 Department of Psychiatry, Yale University NewHaven, CT, USA, 3 Institute of Biomedical Sciences, University ofSao Paulo Sao Paulo, Brazil, 4 Division of Endocrinology, Diabetes& Metabolism, University of Cincinnati Cincinnati, OH, USA,5Epidemiology & Public Health, Yale University New Haven,CT, USAWe are investigating the relative influence of postingestive effects,in contrast to gustatory input, on amino acid vs. carbohydrateintake. Mice knockouts of TRPM5 (KO, [1]), a TRP ion channel,lack behavioral and cranial nerve responses to sweet and L-aminoacid tastants [1]. These animals nevertheless retain the ability todevelop preferences for sipper locations associated with nutrientavailability [2]. We have monitored behavioral, thermogenic andbrain dopamine responses following glucose and L-serine intakein both KO mice and their wild-type counterparts (WT).During short-duration two-bottle tests, WT mice displayedoverwhelming preferences for glucose vs. isocaloric L-serine andL-histidine solutions. In contrast, KO mice exhibited indifferenceto the choices as well as significantly lower levels of intake.However, when allowed to form associations between thepostingestive effects of the solutions and the respective sipperlocations, both KO and WT mice displayed a robust preferencefor sipper locations previously associated with glucoseavailability, compared to isocaloric L-serine. Indirect calorimetryrevealed a close relationship between respiratory quotient valuesand intake levels, suggesting an association between fuelutilization and nutrient selection. Furthermore, microdialysismeasurements revealed nutrient-specific dopaminergic responsesin ventral striatum upon intra-gastric infusions of glucose orL-serine. These preliminary findings suggest that preferences forcarbohydrates over other nutrients can develop independently oftaste quality or caloric load, an effect potentially associated withthe ability of a nutrient to regulate glucose metabolism andstimulate brain dopamine release. Refs. [1] Zhang et al Cell 2003112:293-301. [2] de Araujo et al Neuron 2008 57:930-41.P O S T E R SAbstracts | 47

#P67 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyTaste Receptor T1R3 is Involved in Detection of EthanolFlavor in MiceVladimir O. Murovets 1 , Vasily A. Zolotarev 1 ,Robert F. Margolskee 2 , Alexander A. Bachmanov 31Pavlov Institute of Physiology Saint-Petersburg, Russia,2Mount Sinai School of Medicine New York, NY, USA,3Monell Chemical Senses Center Philadelphia, PA, USAPrevious studies suggested that humans and rodents perceivesweet and bitter components of ethanol flavor, and that in micegenetic differences in ethanol preference depend on allelicvariation of the Tas1r3 gene encoding the sweet-taste receptorprotein, T1R3. The aim of the present study was to examine therole of T1R3 in qualitative taste perception of ethanol bymice. We used mice from the alcohol-preferring strain C57BL/6Jwith either intact Tas1r3 gene (wild-type) or with a null mutationof this gene (knockouts, Tas1R3 -/-). In these mice, consumptionof ethanol solutions was assessed in the long-term 48-h two-bottletest, and then licking responses to ethanol (1.25-20%), sucrose(1-32%) and quinine (0.01-1 mM) were recorded in brief-accesstests using the Davis MS-160 gustometer before and after LiClinducedconditioned taste aversion (CTA) to 10% ethanol wasdeveloped. Compared to wild-type mice, Tas1r3 -/- micedemonstrated concentration-dependent reduction ofconsummatory responses to ethanol in both brief access andtwo-bottle tests, and also had reduced licking rates of sucrosesolutions. The wild-type and Tas1r3 -/-mice had similar lickingresponses to quinine and did not differ in CTA to ethanol, whichgeneralized to quinine, but not sucrose, in mice of bothgenotypes. These data support a conception of two-component(sweet and bitter) taste of ethanol and suggest that perception ofits sweet component depends on the T1R3 receptor, whileperception of its bitter component does not depend on T1R3.Probably, complexity of 10% ethanol flavor and/or salience of itsbitter component prevented generalization of CTA from ethanolto sucrose in this experiment.#P68 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyEffect of kokumi taste active peptides on amiloride-insensitivesalt taste preference in C57BL/6J miceMeeRa Rhyu 1 , Ah-Young Song 1 , Keiko Abe 2 , Vijay Lyall 31Food Function Research Division, Korea Food Research InstituteSeongnam-Si, South Korea, 2 Department of Applied BiologicalChemistry, The University of Tokyo Tokyo, Japan, 3 Physiology,Virginia Commonwealth University Richmond, VA, USAPreviously, we have shown that kokumi taste active peptides (FII)derived from a mature Korean soy sauce modulate salt taste onhuman and the amiloride-insensitive NaCl chorda tympani (CT)taste nerve responses by interacting with TRPV1 variant salt tastereceptor (TRPV1t). To identify the peptides that modulateTRPV1t, FII was further separated into LHa, LHb, LHc, LHd,LHe by column chromatography and their behavioral effects weretested in wild-type C57BL/6J mice using 48h two-bottlepreference tests, in which one bottle contained distilled water andthe other a test solution made with NaCl + 10 M amiloride.Intake of NaCl expressed as the preference ratio. In solutions0-300 mM NaCl containing 10 M amiloride, 150 mM NaCl gavea maximum preference and 300 mM decreased the preference tothe maximum by 50%. In 100 mM NaCl + 10 M amiloride,varying the concentrations of FII (0-1.0%) produced biphasiceffect of NaCl preference. Between 0.1% and 0.5% concentration,FII enhanced NaCl preference, but above 0.5%, FII lowered thepreference. The salt taste modulating effect of FII was transited toLHe: LHe (0.25%) significantly lowered preference for 100 mMNaCl as compared with control (p

#P70 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologySweet Stimuli Elicit Differential Responses in the ChordaTympani Nerve of Obesity-resistant Rats Compared toObesity-prone RatsKimberly R. Smith, David W. PittmanDepartment of Psychology, Wofford College Spartanburg,SC, USAintensity), but had a more complex effect on Na 2 CO 3 (suggestiveof a change in perceived quality and a reduction in perceivedintensity). Taken together with our previous work investigatingbehavioral responses to KCl and sodium gluconate, and combinedsalt appetite and taste aversion work, we conclude that sodiumappetite is driven neither by shifts in quality nor intensity, butrather in a modification of the hedonic valence of a stable perceptof salty taste.P O S T E R SPrevious research has shown that obesity-resistant, S5B/Pl ratsdifferentially prefer carbohydrate diets compared to high-fat dietpreference of the obesity-prone, OM rats. Furthermore, followinga conditioned taste aversion, OM rats appear to be more sensitivein detecting fatty acids. In vitro recordings from taste receptorcells suggest further strain differences such that fatty acids appearto produce more depolarization in the S5B/Pl rats than OM rats;however, in vivo gustatory signaling has not been examined ineither strain. This study characterized afferent gustatoryresponses of the whole chorda tympani nerve in these two strainsof rat using an array of salt (NaCl, KCl), bitter (quinine-HCl),sour (citric acid), umami (MSG), and sweet (glucose, saccharin,glucose+saccharin mixture) taste stimuli at 3 concentrations eachwith and without the presence of a fatty acid in 20-s trials.The addition of 200 µM linoleate tended to produce subtleenhancements of the neural responses to select concentrations ofthe tastants with the most consistent effects on the sweet tastestimuli. The strains showed similar neural responsiveness withineach taste category with the exception of the sweet taste stimuli.The S5B/Pl strain demonstrated greater differences in neuralresponses to glucose, saccharin, and a glucose+saccharin mixturecompared to the OM strain which showed similar responsivenessacross the three sweet stimuli. This difference in the neuralresponsiveness to sweet tastants may underlie the dietarypreference for carbohydrates observed in the S5B/Pl strain.#P71 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyThe Perceptual Consequences Of Salt Appetite In RatsSteven J. St. John, Anya C. Marshall, Erin KrauskopfDepartment of Psychology, Rollins College Winter Park, FL, USAIn rats and other mammals, a physiological sodium deficit leadsto a robust appetite for sodium that is guided by the gustatorysystem. In 1993, Breslin et al. (Am. J. Physiol., 264, R312-8)demonstrated that the inverted-U intake-concentration functionfor NaCl was preserved (but elevated) in salt-deprived rats.They concluded, in contrast to some theories of salt appetite, thatthe perceived taste intensity of NaCl is unchanged during sodiumdeprivation, since a reduction in intensity should produce arightward shift and increases in intensity a leftward shift of theresponse-concentration function. We tested the logic of thisconclusion by examining the responses of salt deprived rats toNa 2 CO 3 , a salt that G.R. Morrison reported was ten times asintense as NaCl to rats (Physiol. Behav., 8, 25-28). Furosemideinjectedrats were tested the following day for their lickingresponses to water and 7 concentrations of Na 2 CO 3 in eitherlow (0.0028 – 0.089 M) or high (0.028 – 0.89 M) concentrationranges. Consistent with Breslin et al. and Morrison, behaviortowards Na 2 CO 3 was an inverted-U shaped lickingconcentrationfunction leftward shifted from NaCl precisely oneorder of magnitude. Amiloride dose-dependently reduced theresponses to NaCl (suggesting a change in perceived quality, not#P72 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyRat as a model for the study of multimodal integrationof flavorShree H. Gautam, Justus V. VerhagenThe John B. Pierce Laboratory New Haven, CT, USANeuroimaging studies in humans have revealed that formation ofa flavor percept involves taste-odor integration. It has also beenestablished that retronasal olfaction and flavor experience playkey roles in this process. Little is known about the detailed neuralcircuitry and mechanisms underlying retronasal stimulus coding,experience and sensory integration of flavor. Since the use ofhumans precludes necessary invasive experimental procedures andcontrol of flavor experiences, we are establishing the use of rats toexplore the neuro-behavioral mechanisms of flavor perception.By optical calcium imaging of olfactory bulb responses to orallypresented odorants in awake behaving rats we ask whether andhow rats smell retronasally, and how this compares to orthonasalolfaction. We found evidence for bulbar responses to oralodorants. Both fast sniffing and fast licking attenuate ortho- andretronasal OB responses, but presumably by different means.Olfactory receptor neurons may be over-stimulated during rapidsniffing, and under-stimulated during licking and swallowing.Behaviorally, by employing conditioned odor and taste aversions,we asked whether the perceived smell of “sweet” odorants issimilar to “sweet” tastants to flavor-naive rats. Retronasalodorants (benzaldehyde and tasteless amyl acetate, CS) did notgeneralize to the prototypical tastants in naive rats. Sucrose (CS)also did not generalize to the odorants. However, the priorexperience of either odor-taste pair did result in specificgeneralization of the odorant to sucrose, suggesting a primary roleof paired odor-taste experience in the formation of flavor objects.Both lines of enquiry provide direct evidence for retronasalolfaction in rats. Thus, the rat emerges as a useful model forextensive flavor research in mammals.#P73 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyMouse Strain Differences in Conditioned Taste AversionFormation, Generalization and Extinction using aSelf-administration ParadigmApril R. Glatt, Kenichi Tokita, John D. Boughter, Jr.University of Tennessee Health Science Center Memphis,TN, USATraditional approaches to conditioned taste aversion (CTA)learning have employed pairing of a novel taste with i.p. injectionsof LiCl. However, a self-administration model involvingcontinuous licking of a LiCl solution is more comparable tonaturally developed food aversions, and allows for temporalAbstracts | 49

analysis of CTA processing (Baird et al., 2005). In this study, weanalyzed acquisition, expression and extinction of CTA inC57Bl/6J (B6) and DBA2/J (D2) mice by examining lickingbehavior to LiCl and NaCl solutions. In preliminary studies withwater-restricted mice, we obtained baseline values for waterlicking and established that B6 and D2 mice respond equivalentlyto concentration series of NaCl and LiCl in brief access tests.Methods: Water-restricted mice were trained to lick water in theMS160 lickometer. On conditioning day, mice received a 20-mintrial with either 0.12M NaCl or LiCl. For 6 days followingacquisition, mice received a 20-min trial of 0.12M NaCl. Results:On conditioning day, mice from both strains responded similarlyto NaCl and LiCl in the first minute, suggesting these stimuli arecomparable in taste. All mice receiving LiCl rapidly formed anaversion beginning in the second minute; D2 mice displayedcomplete aversion by minute 3, while B6 showed this by minute6. On the following day, both strains avoided NaCl relative tocontrols; B6 displayed comparable licks to controls by the 4 thminute, while D2s did not show this until the 8 th minute.However, D2 mice showed lick counts close to zero throughoutthe entire trial. Conclusion: B6 and D2 mice can rapidly develop aCTA to LiCl via self-administration in a lickometer. The CTAgeneralizes to NaCl the next day, but extinguishes, with B6 miceshowing a faster rate of extinction than D2 mice.#P74 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyBeyond Tas1r3: Identification of other loci affectingconsumption of sweet-tasting compoundsNatalia P. Bosak, Maria L. Theodorides, Cailu Lin, ZakiyyahSmith, Gary K. Beauchamp, Alexander A. BachmanovMonell Chemical Senses Center Philadelphia, PA, USAInbred mouse strains differ in their responses to sweet tastestimuli. Although allelic variation of the Tas1r3 locus is partiallyresponsible for these differences, our genetic analyses usingC57BL/6ByJ (B6) and 129P3/J (129) strains suggests that otherloci are also involved and that some of them are sweetenerspecific.We have further studied such loci using an F2 intercrossbetween B6 inbred and 129.B6-Tas1r3 congenic mice andsubsequent selective breeding. F2 mice varied in consumption ofthe 30 mM glycine and 20 mM saccharin and there was nocorrelation between these two traits. From the F2 generation, westarted selective breeding of two pairs of lines: with high and lowsaccharin intakes, and with high and low glycine preferences. Thephenotype-based selection resulted in divergence between thesepairs of lines, which confirms presence of loci polymorphicbetween the B6 and 129 strains. To refine positions of these loci,we have genotyped mice from the 10th and 8th generations ofselective breeding with markers on chromosomes, which werepreviously linked to glycine preference and saccharin intake,respectively. For all chromosomes, there was a significantdivergence of frequencies of alleles in these regions. For glycineselection, mice from the High line accumulated B6 alleles in Chr2,7 and 12, and 129 alleles in Chr14. For saccharin selection, micefrom the High line accumulated B6 alleles in Chr1, 3 and 13, and129 alleles in Chr2 and 7. Mice from the Low lines accumulatedalleles from the opposite strain at these locations. This observationsuggests a complex genetic architecture of behavioral tasteresponses to sweeteners. There are two distinct sets of genesregulating glycine and saccharin consumption and each parentalstrain contributes loci increasing or decreasing a trait value.#P75 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyThe Benzamil (Bz)-insensitive NaCl Chorda Tympani (CT)Taste Nerve Responses Demonstrate Increased Sensitivity toTRPV1t Modulators in Alcohol-preferring (P) RatsVijay Lyall, Tam-Hao T. Phan, Shobha Mummalaneni, PamelaMelone, Jamison Coleman, John A. DeSimoneDepartment of Physiology and Biophysics, VirginiaCommonwealth University Richmond, VA, USAEthanol (ETH), nicotine (NIC) and resiniferatoxin (RTX),modulators of TRPV1t, induce biphasic effects on rat BzinsensitiveNaCl CT responses. At low concentrations theyenhance and at high concentrations inhibit the NaCl CT response.To investigate if chronic ethanol ingestion and genetic preferencefor ethanol are related to alterations in the Bz-insensitive NaClCT responses, we investigated the effect of ETH, NIC and RTXon the Bz-insensitive NaCl CT responses in alcohol-preferring(P) and alcohol nonpreferring (NP) rats. In naïve P rats ETH,NIC and RTX concentration versus the magnitude of the BzinsensitiveNaCl CT response curves were significantly higherand were shifted to the left on the agonist concentration axisrelative to NP rats. This suggests that alcohol preference increasesthe sensitivity of TRPV1t to stimulation by various agonists.P and NP rats were adapted to chronic oral ethanol ingestionusing the sucrose fading paradigm. When adapted to 5% ethanol,P rats consumed significantly more ethanol than NP rats givenfree access to ethanol alone or when given a choice betweenethanol and water. NP rats given oral 5% ethanol for 2 weeks theRTX concentration versus the Bz-insensitive NaCl CT doseresponse curve was higher and shifted to the left on theconcentration axis and was not different from the responseprofiles observed in naïve P rats or P rats given 5% ethanol.These results suggest that upon chronic ethanol consumption NPrats develop the phenotype of P rats related to TRPV1t activity.We conclude that TRPV1t activity is modulated by both ethanolconsumption and genetic preference for alcohol.#P76 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyCentral neural sensitivity to ethanol and other taste stimuliin selectively bred ethanol-preferring and ethanol-nonpreferringratsChristian H Lemon 1 , Susan M Brasser 21St. Louis University School of Medicine Saint Louis, MO, USA,2San Diego State University San Diego, CA, USAA strong positive relationship has been found in mammals forpreference and intake of ethanol and sweet-tasting substances.Ethanol is an ingested drug and its first direct interaction with thebody is orosensory. Data from randomly bred rats indicate thatorally-applied ethanol stimulates neural substrates for sweet taste,which are known to activate forebrain systems associated withreward. Yet it is unknown how ethanol’s appetitive sweet tasteproperties play into the array of variables that influence alcoholingestive reinforcement. Here, we made in vivoelectrophysiological recordings from central gustatory neurons inselectively bred ethanol-preferring (P) and ethanol-non-preferring(NP) rats (Lumeng et al. 1977) to determine if a relationship existsbetween genetically-mediated alcohol preference and the neuralprocessing of ethanol taste. Rats were anesthetized and taste50 | AChemS Abstracts 2009

esponses (net spikes) evoked by applying ethanol (3, 5, 10, 15, 25and 40% v/v) and standard stimuli (including [in M] 0.5 sucrose,0.1 NaCl, 0.01 HCl and 0.01 quinine) to the tongue and palatewere recorded from single neurons in nucleus tractus solitarius.Neurons were also tested with a concentration series of sucrose(0.01, 0.03, 0.1, 0.3 and 1 M) and various other stimuli (fructose,glucose, a sucrose/quinine mixture and individual components ofthis mixture, KCl, citric acid, NaNO 3 , nicotine and MgCl 2 ). Thusfar, 14 neurons have been recorded from P rats and 6 cells fromNP rats. Preliminary analyses reveal that ethanol produces salient,concentration-dependent activation of NTS cells in both P andNP (F 5,90 = 24.48, P

induced by intranasal application of 5% ZnSO 4 with 5%lidocaine. Then, conditioned taste aversion (CTA) to 10% ethanolwas induced using LiCl, and testing in the gustometer wasrepeated. In separate groups of control and anosmic mice longtermconsumption of ethanol solutions was assessed in 48-htwo-bottle test. We have shown that 10% and stronger ethanolsolutions were avoided in both long-term and brief access tests byintact naïve 129P3/J mice, but not by anosmic mice. This suggeststhat an odor of ethanol is a principle signal for ethanol avoidancein both brief-access and long-term tests. Anosmia did not changeunconditioned licking responses to aversive quinine and palatablesucrose, and did not interfere with development of CTA toethanol. Our data suggest that mice use both gustation andolfaction for chemosensory detection of ethanol, and thatolfactory input plays the primary role in ethanol avoidance.#P80 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyMaillard Reacted Peptides (MRPs) Modulate Benzamil (Bz)-insenstive NaCl Chorda Tympani (CT) Taste Nerve Responsesand Blood Pressure (BP) in Dahl Salt-sensitive RatsShyama Masilamani 1 , Jamison Coleman 2 , Pamela Melone 2 ,Shobha Mummalaneni 2 , Tadayoshi Katsumata 3 , John ADeSimone 2 , Vijay Lyall 21Department of Medicine Division of Nephrology VCURichmond, VA, USA, 2 Department of Division of Physiology andBiophysics VCU Richmond, VA, USA, 3 Kyowa hakko Food Sp.Co. LTD Ibaraki, JapanMRPs conjugated with galacturonic acid (GalA-MRP) producebiphasic effects on the rat Bz-insensitive NaCl CT responses.At low concentrations (0.1-0.25%) GalA-MRP enhances and athigh concentrations (0.3-1.5%) inhibits the Bz-insensitive NaClCT response. The maximum enhancement and inhibition of theNaCl CT response was obtained at 0.25% and 1.5% GalA-MRP.We hypothesize that at these concentrations GalA-MRP can beused as a salt taste enhancer and a salt taste suppressor,respectively. Accordingly, the effect of 0.25% and 1.5% GalA-MRP was tested on BP in Dahl salt-sensitive rats fed a dietcontaining 0.3% NaCl. Radio-telemetry blood pressuretransmitters were surgically implanted in rats to monitor theirmean arterial pressure (MAP) in conscious, unrestrained rats for15s every 15 min over a 24 hr period. The average daytime (7 AMto 7 PM) and nighttime (7 PM to 7 AM) MAPs were recorded foreach 24 hr period. Rats maintained on rat chow containing 0.3%NaCl demonstrated a slow rise in their nighttime MAP over a 2week period (0.5-1.6 mm Hg/day). The spontaneous increase inMAP was inhibited when rats were fed 0.3% NaCl dietcontaining 0.25% GalA-MRP over a period of 4 weeks (0.05-0.17mm Hg/day). Following removal of the MRP from the diet, MAPincreased at the rate of 0.3-2.0 mm Hg/day for 2 weeks. In rats fed0.3% NaCl diet containing 1.5% GalA-MRP the MRP increasedat a rate of 0.89±0.17 mm Hg/day relative to 0.22±0.05 mmHg/day in rats maintained on 0.3% NaCl diet alone (mean±SEM;p

These findings demonstrate the capacity of EX-4, a GLP-1agonist to reduce preference for palatable sucrose solutions, andsuggest diminished sensitivity to the postoral component of thiseffect in DIO rats maintained on high fat diet. These observationstogether with data showing an attenuated GLP-1 release after ameal and an increased preference for sweet in obese individualssuggest a causal link between diminished intestinal GLP-1feedback and orosensory sensitivity to sweet, and may also helpwith promoting a novel application for GLP-1 agonists to combatsweet cravings and overeating.#P83 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyState-dependent Yeast Intake in Drosophila melanogasterOsama Ahmed, Beth Gordesky-Gold, Paul A. S. BreslinMonell Chemical Senses Center Philadelphia, PA, USASpecific hungers may arise as a result of metabolic stress. Forinstance, it has been shown that protein-malnourished humanbabies prefer soups that are high in protein over plain or sucrosefortifiedsoups. We aim to utilize the fruit fly as a genetic model ofthe human nutritional need and appetite for protein. Mostinfamously, female mosquitoes require a blood meal prior to egglaying. In the current study, we sought to determine if nutrientintake of Drosophila melanogaster is affected in a similar way.Mated, virgin, and male wild type Drosophila melanogaster weregiven a choice between equivalent concentrations of yeast andsucrose solutions. Mated flies showed greater consumption ofyeast than virgin females or male flies, while sucrose ingestionremained similar among all three groups. The increase in yeastintake indicates an initial preference for yeast over sucrose.However, yeast preference was not stable throughout theexperiment but rose and fell, behavior consistent with egg laying.These results suggest a state-dependent protein appetite in matedDrosophila, which may result from alterations in nutritional needsas the organism prepares for oviposition.#P84 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyA Behavioral Assay using Drosophila to Test forChemesthetic Irritants Activating TRPA1 ChannelsWayne L. Silver, Matthew W. Greene, Paige M. Roe, Erik C.JohnsonWake Forest University Winston-Salem, NC, USAChemesthesis is the sense of irritation produced by chemicals. Inmammals, the trigeminal nerve mediates chemesthesis in the headand face. Chemical irritants stimulate the trigeminal nervethrough a variety of receptor proteins, including TRPA1 which isactivated by over 90 compounds. Fruit flies, Drosophilamelanogaster, possess a painless gene which is the homolog ofmammalian TRPA1. We compared behavioral responses toirritants in wild-type and painless mutant flies in a feeding choiceassay (Al-Anzi et al, 2006) to determine whether irritants whichactivate trigeminal nerve responses in mammals also stimulate flyTRPA1. A 96-well plate served as the test arena with half the wellscontaining sucrose and blue dye and the other half containingsucrose plus irritant and red dye. In half of the tests, the color ofthe food choice was reversed to eliminate color preference.Fifty flies were starved for 24 hours, and then released into thetest arena. After one hour of feeding, the flies were examinedunder a microscope to determine what they ate. Flies were scoredfor blue, red or purple abdomens. The number of flies consumingeach food choice was quantified and a preference index was usedto determine which chemicals the flies avoided. Elevencompounds were tested at a concentration of 5mM. Eight of thesecompounds elicited significantly different responses in the wildtypeand painless mutant. These included allyl-isothiocyante,eugenol, nicotine, a-terpineol, amyl acetate, benzaldehyde, andd-limonene. Acetic acid, toluene, and cyclohexanone did notproduce significantly different responses. These results are similarto descriptions of the chemical sensitivity of mammalian TRPA1.Thus, this fruit fly assay might serve as a useful screen fortrigeminal nerve irritants which activate TRPA1.#P85 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyIntake of Fructose and Sucrose Solutions as aFunction of ConcentrationJennifer A. Cassell, James C. Smith, Thomas A. HouptProgram in Neuroscience, The Florida State UniversityTallahassee, FL, USAThere have been few direct comparisons of fructose (F) andsucrose (S) intake to determine differences in drinking patternsacross multiple isocaloric concentrations. Adult male SD rats(275-300g) were divided into S and F groups (n=8/group), andindividually housed in “hotel” cages which continuouslymonitored rats’ access to powdered chow (3.6 kcal/g) and numberof licks at each of 2 drinking bottles in 6-s bins. Drinking bottlesand chow were weighed and replenished daily. Each week, ratswere given access to water, a single concentration of sugar (S or F)and chow for 5 days, followed by a 2 day break with chow andwater only. Rats were tested with S (0-1.0M) or F (0-2M)solutions in ascending order. Water intake was negligible whensugar was available. Sugar intake was significantly greater thanbaseline water intake at or above 0.03M S or 0.06M F. Intake as afunction of concentration peaked at 0.25M S (136±15g/d) and0.5M F (138±12g/d). When expressed as caloric density, theconcentration-intake curves for S and F were not significantlydifferent, with a peak at 0.34kcal/g. While S and F intake wassimilar, there was a significant effect of sugar type on chow intakeand lick rate. Sucrose rats decreased chow intake as S increasedabove 0.03M (0.04kcal/g). Fructose rats did not significantlydecrease chow intake compared to baseline and ate significantlymore chow than S rats when drinking 0.08 kcal/g solutions andabove. Thus, cumulative caloric intake was much greater in F rats(3607±63 kcal) than S rats (2025±107 kcal, p

#P86 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyAntennular Waving in Spiny Lobsters is Enhanced byOdorants: A 3D Kinematic AnalysisPeter C. Daniel, Calvin CarterHofstra University Hempstead, NY, USAA major goal of chemosensory guidance research is to elucidatehow animals extract information from the complex spatial andtemporal structure of odorant plumes. Studies using lobsters asmodel organisms have examined orientation and locomotion ofthe whole animal as it encounters odorant plumes, as well as theflicking behavior of the antennules, the olfactory organ.Antennules can also move independently of general bodymovements by adjusting the joints of segments of the antennulesmore proximal to the body than the lateral and medial flagella thatcontain chemosensilla. These movements, referred to asantennular waving, have been observed anecdotally to increase inthe presence of chemical stimuli. This hypothesis was tested bystereoscopic filming of antennular waving of 10 spiny lobsters,Panulirus argus, towards control seawater and squid extract. 3Dkinematic analysis software was used to measure the second bysecond coordinates of antennules and the body over 60 secfollowing stimulus introduction. Antennule coordinates werecorrected for body position. Antennular waving increased about50% upon introduction of squid extract relative to controlresponses. However antennular waving and body movement arepositively correlated independent of stimulus type. Left and rightantennular waving averaged over 60 sec were strongly correlated.However second by second velocities of the two antennules werenot correlated. Thus left and right antennule movements, whilenot synchronized, are both tightly coupled to body movement.We also report preliminary results of ablation studies designed todetermine contributions of nonolfactory and olfactory inputs toantennular waving. These results suggest that antennular wavingcontributes to increased spatial sampling in the presence ofodorants.#P87 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyThe effect of sniffing frequency on odor behaviorKeiichi TonosakiMeikai Univ Sakatoshi, JapanMany animals, such as horses, sheep, dogs, cats, rats and micecommonly exhibit the sniffing behavior when they are searchingthe foods or the odors. It is believed that the sniffing is one of theimportant behaviors in their life. It is possible that change insniffing frequency and (or) strengthen, then the odor samplingbehavior and the olfactory receptor cell responses may be changedand alter higher order coding. Standard respiration rate in rats is1-2 Hz but sniffing varies between 4-12 Hz. Olfactory receptorcells are elicited the responses by the absorption of the chemicalsubstances. We used continuously or intermittent (mimicked thesniffing respiration pattern) application of odor stimulationmethods, and have investigated that changes in sniff frequencycould be changed the level of odor behavior or not, and howsniffing alters odor responses during the different sniffingbehavior.#P88 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyDetailed Analysis of the Effects of Periodic Input on BehavioralMeasures of Odor Detection in the Moth Manduca sextaMandy N. Hatfield , Faizan R. Kalwar , Kevin C. DalyWest Virginia University Morgantown, WV, USAIn mammals, sniffing is an active odor sampling process.In moths, the wing beat oscillates airflow over the antennaeaffecting olfactory input, which may affect sensitivity. To test thishypothesis, we generated concentration response functions usingtrained Manduca sexta moths. Moths were conditioned toassociate a conditioning stimulus (odor; CS) with sucrose usingclassical conditioning. At 24 then 48 hours after conditioning,moths were tested with either a pulsed or continuous CS. Pulsetrains were 4 s long, 20 Hz (the approximate wing beatfrequency), with either a 10:40 ms (ON:OFF) or 40:10 ms dutycycle. Duration of continuous stimuli was normalized to theintegrated pulse duration. Stimuli were presented across a 5 logstepdilution series from low to high. Flow velocity was ~30 or~80 cm/s (speeds consistent with odor-guided flight). To controlfor extinction effects, 5 groups were tested with one dilution. Tocorrect for the total stimulus duration, one group received thecontinuous stimuli at 1/5 the concentration (replicating the 10:40duty cycle). We also statistically normalized responses to percentresponse/ms on-time. To control for stimulus-specific mechanicaleffects, responses to blanks were recorded for both stimuli andused for normalization of odor responses. Results of ANOVAindicated that the percentage of moths responding to the CSincreased significantly as a function of concentration. Importantly,pulsed stimuli significantly enhanced sensitivity to odor; this wastrue across all control groups. Results of these behavioralexperiments support the hypothesis that periodic stimuli increaseodor salience in this moth species.#P89 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyPeriodic Odor Stimulation Affects Antennal Input,Antennal Lobe Processing, and Behavioral Measures ofPerception in the Moth Manduca sextaKevin C. Daly 1 , Shreejoy Tripathy 2 , Erich M. Staudacher 1 ,Oakland J. Peters 1 , Mandy N. Hatfield 1 , Faizan R. Kalwar 11West Virginia University Morgantown, WV, USA, 2 CarnegieMellon University Pittsburgh, PA, USABiomechanical studies of the insect wing beat show that eachdown stroke increases air flow over the antennae. This couldaffect penetration of odor on the sensilla, thus, providing atemporally patterned antennal lobe (AL) input in a manner similarto mammalian sniffing. Does the antenna and AL respond to odorstimulation on a wing beat timescale (18-28Hz) and can this affectperceptual acuity? To address these questions, we varied stimulusfrequency and measured antennal responses in Manduca sextamoths, via electroantennograms (EAGs). Spectral analysis ofEAG responses indicated significant pulse tracking up to 30Hz.Responses to blanks were significant up to 25Hz, but weresignificantly smaller than pulsed odor. Using in vivo multielectrode methods, we show that both AL local field potential andunitary responses tightly track periodic stimuli at wing beatfrequencies. Local field potentials tracked stimuli beyond thewing beat frequency (up to 72Hz). Furthermore ~25% of54 | AChemS Abstracts 2009

ecorded units tracked stimuli up to 30 Hz. Bicuculine (200µMbath applied) abolished AL pulse tracking, suggesting GABA Ainvolvement. Intracellular replication indicated that both local andprojection interneurons track pulses but the reduced “head only”intracellular method yielded tracking to only 14Hz. Finally, usinga conditioned feeding response as a behavioral indicator of odordetection, we showed that moths are more sensitive to odorpulsed at 20Hz, relative to a continuous odor. These resultssuggest that the olfactory system of this moth has evolved torespond to olfactory input defined by the beating wing.#P90 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyAttraction of Female Round Gobies to SteroidsReleased by MalesMatthew R. Kereliuk 1 , Yogesh Katare 1 , Keith Tierney 1 , AlysonLaframboise 1 , Alexander P. Scott 2 , Barbara S. Zielinski 11Department of Biological Sciences, University of WindsorWindsor, ON, Canada, 2 Weymouth Laboratory, The Centre forEnvironment, Fisheries and Aquaculture Science Weymouth,United KingdomThe objective of this study is to evaluate the femalechemoattractant property of isolates derived from male urine orfrom water previously occupied by male round gobies, Neogobiusmelanostomus, which is an invasive fish species to the NorthAmerican Great Lakes. Reproductive (RF) or non-reproductivephase female (NRF) round gobies were placed in isolated 5-Lflow-through tanks and presented with odours via the waterinflow after an acclimation period. The behaviour of the fish wasrecorded then analyzed. Swimming velocity and the amount oftime spent near the odour inflow was determined. Neitherparameter was affected by the delivery of vehicle blanks. The RFincreased the time spent near the odor source when presentedwith urine collected from males previously injected with GnRH,and by fish water excluding urine. Both RF and NRF wereattracted by methanol extracts of male-scented water. NRFsincreased swimming velocity toward and the time spent near anisolate of male-scented water containing the steroid 11-oxoetiocholanolone(11-oxo-ETIO), however RF showed anavoidance swimming reaction to this fraction. In contrast, bothRFs and NRFs spent greater time near the inflow of an isolatecontaining an unknown conjugate of 11-oxo-ETIO. These studiesdemonstrate that females can exhibit reproductive-state specificattraction responses to steroids released by male round gobies,including 11-oxo-ETIO and an unidentified conjugate. We areworking towards identifying the compounds responsible for thisactivity.#P91 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyAndrostenone May Show Pheromonal Activity in MiceVera V. Voznessenskaya, Maria A. KlyuchnikovaA.N.Severtzov Institute of Ecology & Evolution Moscow, Russiadisrupt behavioral reactions. Mice engage in anogenital and/ornaso-oral investigation prior to either initiating sexual advances inthe presence of a female or aggression with an unfamiliar male.We studied a possible relationship between sensitivity toandrostenone (AND) and aggression in NZB/B1NJ (NZB) andCBA/J (CBA) mice. CBA mice are more than 2000-fold sensitiveto AND than NZB mice. Atypical for mice in general, NZB malesoften attacked females. This may imply that chemosensory cuesand social behavior are de-linked in NZB males. Alternatively,NZB mice may have deficits in olfaction that lead to failure todiscriminate sex and social rank of conspecifics. Failure to processbiologically important odors may lead to elevated aggression.In standard odor preference test CBA males showed strongpreference for receptive female odor relative to male odor (n=8).However NZB males did not show preference for the odor fromreceptive female versus odor from male. CBA males showedsignificantly (p

#P93 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologySea hares chemically defend themselves from predatory bluecrabs and bluehead wrasse using light-harvesting moleculesin their algal dietMichiya Kamio, Linh Nguyen, Tiphani V. Grimes, MatthewNusnbaum, Melissa H. Hutchins, Seyma Yaldiz, Robyn van Dam,Charles D. DerbyNeuroscience Institute and Department of Biology,Georgia State University Atlanta, GA, USASea hares, Aplysia californica, release a purple ink secretion whenattacked by predators. This secretion is composed of twosecretions, ink and opaline, and either alone or both together candefend them by affecting chemosensory system of predators. Themolecular identities of the deterrent compounds in the ink remainlargely unknown. We asked two questions: Is A. californica ink achemical deterrent against two predators: blue crabs, Callinectessapidus, and bluehead wrasse, Thalassoma bifasciatum? and if yes,What are the active molecules? Both species were tested in twobehavioral assays: a feeding assay in which animals were offeredfood soaked (or not) in ink; and a cloud assay in which ink wassquirted at the animals. Both assays revealed that fish and crabsare deterred by ink. The identity of the active components in inkwas examined in bioassay guided fractionation using the feedingassay. Aplysioviolin (AV) was identified as the major activecomponent and phycoerythrobilin (PE) was a minor one. AV andPE have similar activities at equimolar concentrations, but becauseaplysioviolin is approximately ten times more abundant in ink,it is the major active component in ink. The structures of thesemolecules were identified using NMR, MS, and UV spectra.PE is a chromophore covalently linked to a protein to form thephotosynthetic pigment of red algae in the diet of Aplysia. AV isthe monomethyl ester of PE. AV and PE are also present in ink ofAplysia dactylomela, a sympatric sea hare with blue crabs andbluehead wrasse, at approximately the same ratio. Thus, sea haresacquire light-harvesting proteins from red algae, cleavephycoerythrobilin from the protein, convert it into aplysioviolin,and store these molecules in the ink gland, and release it aschemical deterrents against predators.from OA levels. Finally, male moth upwind flight ability wasstudied following OA injection, to identify differences insuccessful flight to artificial pheromone lures. Pending results ofthe current study, subsequent efforts will integrate learningparadigms such as the proboscis-extension reflex (PER) todecipher any influence of OA on odour learning.#P95 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyFlavor Identification and Memory in ChildrenMelinda S Brearton, Brittany Carlisle, Katheryn Pointer,Erica Mannea, Konstantin Rybalsky, Robert A FrankUniversity of cincinnati Cincinnati, OH, USAWe have previously shown that identification and memory forjelly bean flavors is improved when flavor labels are providedduring testing. The current study assessed whether similar effectswould be found in children. Children between four and elevenyears old were asked to identify and remember jelly bean flavorsin a joint flavor identification/recognition memory task. In Phase1 the children were given ten jelly beans and asked to identify theflavor of each. They were provided with four alternative flavorlabels and accompanying pictures that matched the labels. Phase 2commenced after a ten minute retention interval. Participantswere presented randomly with the ten jelly beans from Phase 1and ten new jelly beans, and asked to accurately identify eachflavor and indicate whether the jelly bean flavor had beenpresented previously in Phase 1 (old) or was being presented forthe first time (new). We found, as with adults, that identificationand memory performance improved when labels were provided,but the effect was larger for adults. We had previously found thatconsistently labeled old flavors were remembered almost perfectlyby adults. Interestingly, this same relationship was observed forchildren. This suggests that flavor knowledge and experience(rather than differences in cognitive processes) account for theobserved differences between the performance of the childrenand adults.#P94 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyRole of Octopamine in Moth OlfactionKirk HillierAcadia University Wolfville, NS, CanadaOctopamine (OA) is a significant neuromodulator within theinvertebrate nervous system. In many respects, the functional roleof OA is similar to that of other aminergic compounds such asnoradrenaline within vertebrates. This includes a direct influenceon energetic activities, arousal, learning and memory. The currentstudy investigates the effects of OA on the physiology andodour-mediated behaviours of the tobacco budworm moth,Heliothis virescens. First, a neuroanatomical study was conductedto determine the distribution of OA within this species brain,relative to other moth species. Second, OA injections were madeinto the brain and single-sensillum recordings were subsequentlymade from the antennae. In particular, the responses of male andfemale moths to female sex pheromones were compared toidentify any intersexual differences in threshold or spiking evident#P96 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyMillisecond Photoactivation of Bombykol Receptor NeuronsExpressing Channelrhodopsin-2 Triggers PheromoneSearching Behavior in Male SilkmothsMasashi Tabuchi 1,2 , Takeshi Sakurai 1 , Hidefumi Mitsuno 1 ,Ryo Minegishi 1 , Shuichi S. Haupt 1 , Takahiro Shiotsuki 3 , KeiroUchino 3 , Hideki Sezutsu 3 , Toshiki Tamura 3 , Kei Nakatani 2 ,Ryohei Kanzaki 11Research Center for Advanced Science and Technology, TheUniversity of Tokyo Tokyo, Japan, 2 Graduate School of Life andEnvironmental Sciences, University of Tsukuba Tsukuba, Japan,3National Institute of Agrobiological Sciences Tsukuba, JapanOdor-evoked spikes in olfactory receptor neurons (ORNs)induce behavioral responses within a short-timed latency.Therefore, controlling neural activity of targeted ORNs withhigh temporal resolution is important to clarify neural codesunderlying computational circuit and odor-driven behavior.The silkmoth, Bombyx mori, is a useful model for studying theolfactory system because of the straightforward input-output56 | AChemS Abstracts 2009

elationship in the characteristic response (pheromone searchingbehavior) of male moths to pheromone called bombykol releasedby conspecific females. However, little is known about the precisetemporal characteristics of peripheral input in relation to theinitiation of pheromone searching behavior because the difficultyin controlling and administering olfactory stimuli still remain tobe solved. To address the problem, we generated a transgenicsilkmoth expressing channelrhodopsin-2 (ChR2), a blue lightgatedion channel identified in green algae, under the control of aputative promoter sequence of BmOR1, the bombykol receptorgene in silkmoth. ChR2 expressing male displayed typicalpheromone searching behavior in response to a single pulsed bluelight stimulation. Probability of behavioral response wasdependent on duration of stimulation, and response thresholdtime was 3 ms that evoked a single spike in bombykol receptorneurons in single sensillum recordings. When input informationwas decreased by covering a half region of antennae, probabilityof behavioral response was significantly reduced, which recoveredto a normal level by a second stimulation given within a timewindow of approximately 120-240 ms. These results suggest thatthe triggering of behavior is simply determined by the collectiveamount of spiking information summated within few hundredmilliseconds.#P97 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyOlfactory Thresholds of ElasmobranchsTricia L Meredith, Stephen M KajiuraFlorida Atlantic University Boca Raton, FL, USAOlfactory capabilities of elasmobranchs are legendary. Althoughreputed to demonstrate remarkable odor sensitivities, thisperception is based on surprisingly little empiricalevidence. Olfaction plays an important role in the localization ofprey, and amino acids in particular are effective odorants forelasmobranchs. However, olfactory sensitivity has been assessedfor only four elasmobranch species using a handful of aminoacids. Literature values for these species indicate thresholds to beapproximately 10 -7 to 10 -8 M. The aim of this study was to surveythe olfactory thresholds of five phylogenetically diverseelasmobranch species (Dasyatis sabina, Urobatis jamaicensis,Raja eglanteria, Negaprion brevirostris, and Sphyrna tiburo) inorder to develop a representative picture of their olfactorycapabilities. The electro-olfactogram (EOG) technique was usedto assay the sensitivities of these species to a suite of twentyproteinogenic amino acids. Both the relative stimulatoryeffectiveness of the tested amino acids and their estimatedthresholds (~10 -7 to 10 -9 M) across all five tested elasmobranchspecies were similar. These results indicate that elasmobranchspecies do not demonstrate greater olfactory sensitivity thanteleost fishes.#P98 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyCycloheximide: an effective taste aversion UCSBradley K Formaker, Kumudini Chintalapati, Thomas PHettinger, Marion E FrankUniversity of Connecticut Health Center Farmington, CT, USAA single oral exposure to 0.5 mM cycloheximide (Cyx) results inan increased aversive behavioral potency towards Cyx (Hettingeret al., 2007). To test if this increased potency is the result of denovo taste receptor induction or the ability of Cyx to act as anunconditioned stimulus in aversion learning, we behaviorallytested 4 groups (n=6) of golden hamsters (Mesocricetus auratus)and electrophysiologically recorded from 2 groups. All behavioralanimals were maintained on a restricted water drinking schedulethroughout the experiment. One group drank 100 mM sucrosebefore injection with 0.5 mM Cyx (mixed in 154 mM NaCl; 12.4ml/kg bw; ip). This dose approximates the amount of 0.5 mM Cyxnaïve hamsters ingest in 1 hr. A control group drank 100 mMsucrose before injection with 154 mM NaCl. A second controldrank distilled water before injection with Cyx and the last groupdrank 0.5 mM Cyx before injection with NaCl. Hamsters exposedto sucrose and injected with Cyx showed robust behavioralavoidance to sucrose (~80% suppression) compared to all othergroups, which did not differ from each other. The sucroseaversion remained robust through 4 weeks of testing. Chordatympani (CT) responses were recorded in 2 groups (n=3) ofhamsters culled from the 4 behavioral groups. One group wasorally exposed to 0.5 mM Cyx and the other group was notexposed to Cyx at all. Cyx failed to activate the CT atconcentrations up to 1 mM, regardless of Cyx exposure.These results suggest that the increased aversive behavior towardsCyx, following initial exposure, is due to the effectiveness ofCyx as an unconditioned stimulus in aversion learning.#P99 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyEnantioselective Odorant Receptor in the Yellow FeverMosquito, Aedes aegyptiJonathan D. Bohbot, Joseph C. DickensUSDA, ARS, BARC, PSI, IIBBL Beltsville, MD, USAEnantiomers, non-superimposable mirror image molecules, havebeen shown to drive important behaviors of a wide range oforganisms from insects to humans. Enantiomer recognition ispredicated on the organism’s capability to discriminate thesechiral olfactory signals. The existence of enantiomer-specificreceptors in other molecular recognition processes and theextensive body of physiological evidence for such mechanisms inolfaction have long argued for the existence of enantiomer-specificodor receptors. Using the two-microelectrode voltage clamptechnique with Xenopus oocytes expressing the mosquito Aedesaegypti OR8 (AaOR8), we were able to show for the first timedirect evidence that an insect receptor discriminates the twoenantiomers of 1-octen-3-ol. Not only is AaOR8 enantioselective,but proper chain length and degree of unsaturation are alsoimportant chemical features necessary for its full activation. Thisenantioselective odorant receptor provides a molecular basis forthe chiral specificity exhibited by insect olfactory sensoryneurons. This work was supported in part by a grant to J.C.D.P O S T E R SAbstracts | 57

from the Deployed War Fighter Protection (DWFP) ResearchProgram, funded by the US Department of Defense through theArmed Forces Pest Management Board (AFPMB).#P100 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyRelationships between Early Dietary Experiences andAcceptance of the Basic Tastes during InfancyCatherine A. Forestell 1,2 , Gary K. Beauchamp 1 , Julie A. Mennella 11Monell Chemical Senses Center Philadelphia, PA, USA,2The College of William & Mary Wiliamsburg, VA, USATo evaluate individual differences in acceptance and facialreactivity to the basic tastes, we studied an ethnically diversesample of newly weaned infants (N=36), who were between theage of 5 and 10 months. The infants, all of whom had experienceeating table foods, were tested for their acceptance of exemplars ofthe five basic taste qualities in a familiar food matrix (i.e., infantcereal). The methodologies used were developed and validated atthe Monell Center and controlled for a number of factors to allowfor the evaluation of infants’ hedonic responses independently ofthe caregiver and experimenter. Our results indicate that there wasa great deal of variability in the types of table foods that infantsconsumed at home as well as in their behavioral responses to thetastants. In general, the number of distaste expressions displayedduring the first two minutes of feeding was predictive of infants’overall consumption (p’s S > 250G > W; 333G+S > S >333G > W. Note that for each concentration of G, the relative oralstimulation was G+S > S > G > W. Experiment 2 determinedwhether the relative amount of oral stimulation reliably predicteddaily intake of each solution. We observed the following relativeintakes: 167G+S > 167G = S > W; 250G+S > 250G > S > W;333G+S = 333G > S > W. Note that the measures of oralstimulation failed to predict the pattern of daily intakes, and thatthe discrepancy between oral stimulation and daily intakeincreased with concentration of G. In fact, 333G and 333G+Sboth stimulated daily intakes > 1.4 times the body weight of themice. These data show that the contribution of post-oralstimulation to daily glucose intake increases dramatically withconcentration.#P102 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyIntensity of 6-n-propylthiouracil (PROP) Taste, FoodPreferences, and Obesity: The Beaver Dam Offspring StudyKaren J Cruickshanks 1 , Carla R Schubert 1 , Derek J Snyder 2,3 ,Linda M Bartoshuk 2 , Guan-Hua Huang 4 , Barbara EK Klein 1 ,Ronald Klein 1 , Elizabeth M Krantz 11Unvversity of Wisconsin School of Medicine and Public HealthMadison, WI, USA, 2 University of Florida Gainesville, FL, USA,3Yale University New Haven, CT, USA, 4 National Chiao TungUniversity Hsinchu, TaiwanBackground:The intensity of the response to PROP mayinfluence food preferences and dietary intake, but fewepidemiologic studies have evaluated taste. As part of the BeaverDam Offspring Study (BOSS), a study of sensory aging, theassociations of PROP taste intensity to food preferences andweight were evaluated. Methods:Adult children of participants inthe population-based Epidemiology of Hearing Loss Study, alongitudinal study of aging, were eligible for the BOSS (n=3285;mean age =49 yrs). PROP filter paper disks (1.2-1.6 mg) wereused to measure intensity on a generalized labeled magnitudescale (gLMS). Food dislikes/likes were assessed with a hedonicgLMS. Questionnaire data about lifestyle factors were obtainedand height, weight, and waist circumference measured.Standardized PROP scores were analyzed as groups (low, mid andhigh responders). Results: The taste quality of the disk was calledbitter by 83% of the high PROP group; 99.6% of those in the lowgroup selected the “no taste” response. High PROP respondersrated salted pretzels (3.16, p=0.04), sweets (3.87, p=0.02) andsausage (5.05, p=0.004) higher (liked more) on the dislikes/likesscale and rated dark chocolate (-6.09 p=0.02), and grapefruit juice(-4.93, p=0.03) lower (disliked more) than mid and lowresponders. High compared to mid/low PROP was associatedwith adding salt to food less often (Odds Ratio (OR)=0.74,95%Confidence Interval (CI)=0.59, 0.92) and smoking (OR=1.50,95%CI=1.17, 1.94). PROP was not associated with current BodyMass Index or waist circumference. Conclusions: PROP responsein the general population was associated with differences in likingand disliking foods and may be associated with salt use andsmoking. Longitudinal data are needed to understand the impactof PROP intensity on health.58 | AChemS Abstracts 2009

#P103 Poster session II: Chemosensory response to,and control of, feeding/NeuroethologyPerception of Threshold and Suprathreshold Taste Stimuli inObese and Normal-Weight WomenM. Yanina Pepino 1,2 , Susana Finkbeiner 1 , Gary K. Beauchamp 1 ,Julie A. Mennella 11Monell Chemical Senses Center Philadelphia, PA, USA,2Washington Univerisity in St. Louis, School of Medicine St. Louis,MO, USAThe goal of the present study was to determine whether obesewomen exhibit altered umami and sweet taste perception whencompared to normal weight women. To this end, each of 56subjects participated in a two-day study separated by one week.Half of the women were evaluated using mono sodium glutamate(MSG; prototypical umami stimulus) on the first test day andsucrose on the second test day; the order was reversed for theremaining women. We used two-alternative forced-choicestaircase procedures to measure taste detection thresholds, aforced-choice tracking technique to measure preferences, thegeneral Label Magnitude Scale to measure perceived intensity ofsuprathreshold concentrations and a triangle test to measurediscrimination between 29mM MSG from 29mM NaCL. We findthat although obese women required a higher concentration ofMSG to detect a taste, their perception of MSG at suprathresholdconcentrations, their ability to discriminate MSG from salt, andtheir preference for MSG and sweets were similar to that observedfor normal-weight women. Regardless of their body weightcategory, 28% of the women did not discriminate 29 mM MSGfrom 29 mM of NaCl (Non Discriminators). Surprisingly, wefound that Non Discriminators at suprathreshold MSGconcentrations had similar MSG detection thresholds thanDiscriminators. Taken together, these data suggest that differentmechanism may be involved in the perception of threshold andsuprathreshold MSG concentrations.#P111 Poster session II: Cortical chemosensoryprocessing/Receptor genomics and molecular biologyGroup III metabotropic glutamate receptors modulatetransmission of taste information in primary taste afferentsRobert M HallockUniversity of Colorado School of Medicine Aurora, CO, USAPrimary afferent taste fibers use glutamate as the majortransmitter at their central terminals in the nucleus of the solitarytract (nTS). We investigated the role of metabotropic glutamatereceptors (mGluR) in regulating transmission in the primarygustatory nucleus of goldfish, the vagal lobe (homologous to thevagal gustatory portion of the nTS in mammals). We used an invitro slice preparation of the vagal lobe to determine the effects ofmGluR agonists/antagonists in transmission of gustatoryinformation. In this preparation, primary gustatory afferents wereelectrically stimulated, while evoked dendritic field potentials(fEPSP) were recorded in the sensory layers of the vagal lobewhere the afferents terminate. We have previously shown that anmGluR agonist (L-AP4) attenuates synaptic components of thefEPSP to electrical stimulation of the primary taste afferent fibers.Here, we extended these findings by examining responses to anmGluR antagonist, MAP4. In Experiment I, we confirmed thatL-AP4 significantly depressed the fEPSP. Then, the addition ofMAP4 reversed the inhibitory effects of L-AP4 (p

#P105 Poster session III: Cortical chemosensoryprocessing/Receptor genomics and molecular biologyAnterior Olfactory Nucleus: A Golgi Study ofDendritic MorphologyPeter C. Brunjes, Michael KenersonUnivesrity of Virginia Charlottesville, VA, USAThe anterior olfactory nucleus (AON) is the first bilaterallyinnervated structure in the olfactory system. It is typically dividedinto “pars principalis“, a thick ring of cells that surrounds theremnant of the olfactory ventricle [usually subdivided into parsmedialis (“pm“), dorsalis (“pd“), lateralis (“pl“) and ventroposterior(“pvp”)] and “pars externa“, a thin ring of cells encirclingthe anterior aspect of the structure. Little is known about theinternal structure of either region. We performed a quantitativeGolgi study to provide the first detailed look at the resident cells.Brains from 8 juvenile rats were stained with the Golgi-Coxmethod and sections counterstained with methyleneblue. Neurolucida ® software was used to reconstruct the cells andsubject them to standard “branch” and “Sholl” analyses. A totalof 206 “pyramidal”-type cells were examined in pars principalis(68 from deep, 71 from middle and 67 from the superficial thirdsof Layer II, and further keyed as to location (19; pm, 73; pd, 86 ;pl, and 28; pvp). Preliminary analyses indicate no deep-superficialdifferences in total dendritic length or number of branches(medians: apical 855µm length and 18 branches, basilar: 17branches, 430 µm length). Two varieties of cells in pars externawere also examined: the typical cell with two apical dendritesextending into Layer Ib (sample = 50 cells: total dendritic length:894 µm) and a second, complex cell with more primary apicaldendrites plus basilar processes (26 cells: total apical length:944 µm, basilar length 605 µm). Other less common cells werealso observed, but due to the lack of a large sample were notsubjected to a quantitative analysis. The results provide importantinformation for understanding and modeling the circuitry ofthe AON#P106 Poster session III: Cortical chemosensoryprocessing/Receptor genomics and molecular biologyDetecting the taste-specific temporal type byfMRI – salty and sweet-Yuko Nakamura 1 , Tazuko K Goto 1 , Kenji Tokumori 1 , TakashiYoshiura 1 , Koji Kobayashi 2 , Yasuhiko Nakamura 2 , HiroshiHonda 1 , Yuzo Ninomiya 1 , Kazunori Yoshiura 11Kyushu University Fukuoka, Japan, 2 Kyushu UniversityHospital Fukuoka, JapanTaste perception has a temporal dimension. The sensoryevaluation in humans showed that, for example, the reaction timeis shorter in salty than in that of sweet. The purpose of this studywas to investigate the differences between salty and sweet intemporal neural responses in the human cortex. For this purpose,we used a new temporal model analysis to demonstrate thetemporal parcellation of brain activity by whole brain analysis viafMRI. Healthy volunteers (ten males and ten females, 19-29 yrs ofage) participated in this study, and all images were acquired with a3.0-T MRI. Salty (0.1M sodium chloride) and sweet (0.5Msucrose) were used as tastants and tasteless artificial saliva (25 mMKCl plus 2.5 mM NaHCO 3 ) as the control. Image data analysiswas performed using the SPM5. First, we analyzed fMRI datasetsby using the standard approach model, and confirmed that theactivated areas of both tastants were located on the putativehuman primary taste cortex (uncorrected P

#P108 Poster session III: Cortical chemosensoryprocessing/Receptor genomics and molecular biologyThe effect of unilateral naris occlusion on gene expression inthe mouse olfactory mucosa and bulbDavid M. Coppola 1 , Yan Zhang 2 , Oswald R. Crasta 21Randolph Macon College Ashland, VA, USA, 2 BioinformaticsInstitute Blacksburg, VA, USAUnilateral naris occlusion (UNO) has been the most commonmethod of effecting stimulus deprivation in studies of olfactoryplasticity. However, in the >100 years that have elapsed since thefirst reported UNO experiment, many contradictory results haveaccumulated. Early experiments focused on deleterious effectsassumed to be due to the stimulus restriction that undoubtedlyaccompanies UNO. More recently, a number of studies havepointed to ‘compensatory’ effects of UNO. Unfortunately, fewdata are available on indirect UNO effects, i.e. those unrelated toodor deprivation. Modern high-throughput methods such asmicroarray analysis may help rectify the deficits in ourunderstanding of UNO phenomenology as well as revealing newavenues to study olfactory plasticity specifically and neuralplasticity more generally. Here we report the results of the firstknown analysis of genome-wide effects on olfactory mucosa andbulb induced by UNO using the Affymetrix 430.2 chip set. RNAwas extracted from pooled tissue samples of 25-day-old femaleCD-1 mice using the Qiagen RNA easy kit. Some subjects hadreceived UNO on the first postnatal day. The three treatmentconditions: UNO open side, UNO occluded side, and untreatedmice, were run in triplicate for mucosa and in duplicate for bulbusing different groups of animals. Chip data were normalizedusing the gcRMA method and only genes that showed both atwo-fold change and a p-value of

#P112 Poster session III: Cortical chemosensoryprocessing/Receptor genomics and molecular biologySubnuclear organization of parabrachial taste neuronsprojecting to reward-related forebrain structures inC57BL/6J miceKenichi Tokita, John D. BoughterUniversity of Tennessee Health Science Center Memphis,TN, USASensations elicited by taste involve not only qualitative, but alsohedonic evaluation of stimuli. In fact, feeding and drinkingbehaviors of animals including humans are largely based on thisaffective evaluative outcome. Although the neural pathwaysunderlying these processes have not yet been well clarified, it isthought that taste information is conveyed to the reward systemof the brain, whose essential components are the ventral tegmentalarea (VTA) and nucleus accumbens. Neurons in the pontineparabrachial nucleus (PbN), the second taste relay in rodents,send axons to the ventral tegmental area as well as to the forebraingustatory areas such as the gustatory thalamus (VPMpc), centralnucleus of the amygdala, bed nucleus of the stria terminalis andinsular cortex. However, it is not clear whether 1) VTA-projectingneurons in the PbN also send axon collaterals to forebraingustatory areas, and 2) these neurons are taste-responsive. In thecurrent study, we performed functional neuroanatomicalexperiments combining c-Fos immunochemistry and retrogradetracing techniques to understand how the taste system interactswith the reward system in the mouse, an animal model withincreasing importance in various fields of neuroscience. Theretrograde tracers Fluorogold (FG) and cholera toxin subunit b(CTB) were iontophoretically injected into the VTA and VPMpcrespectively, and retrogradely-labeled neurons and sucroseevokedc-Fos expression in the PbN were visualized withimmunofluorescence. Some neurons were double labeled with FGand c-fos or triple labeled with FG, CTB, and c-fos. These resultssuggest that taste neurons in the PbN project both to the taste andreward systems. This work was supported by DC000353.#P113 Poster session II: Cortical chemosensoryprocessing/Receptor genomics and molecular biologyCloning and Localization of Four Putative SerotoninReceptors in the Primary Olfactory Pathway of theMoth Manduca sextaWujie Zhang 1 , Mike A. Miller 1 , Akshay Muralidhar 1 , Joel B.Dacks 2 , Andrew M. Dacks 1 , Alan J. Nighorn 11Arizona Research Laboratories, Division of Neurobiology,University of Arizona Tucson, AZ, USA, 2 Department of CellBiology, University of Alberta Edmonton, AB, CanadaSerotonin (5-hydroxytryptamine, or 5HT) functions as aneuromodulator in the antennal lobes (ALs; the primary olfactorycenter) of the moth Manduca sexta. To elucidate the molecularand cellular mechanisms behind the physiological effects of 5HTin the AL, and to further our understanding of its modulatoryrole, we are studying 5HT receptors in the primary olfactorypathway of Manduca. We previously reported the cloning of twoputative 5HT receptors from Manduca, Ms5HT1A andMs5HT1B. We cloned a third putative 5HT receptor, Ms5HT7,and partially cloned a fourth putative 5HT receptor, Ms5HT2.Using sequence analysis, we demonstrate that the full length andpartial clones exhibit high similarity to characterized 5HT7 and5HT2 receptors (respectively) from other insects. Using RT-PCR,we have determined that all four putative 5HT receptors areexpressed in both the AL and antenna of adult moth. We havegenerated antisera against Ms5HT1A and Ms5HT1B; Westernblots of AL tissue using the Ms5HT1A and Ms5HT1B antiseraproduced single bands at 51kDa and 48kDa, respectively. Inaddition, we have generated riboprobes for Ms5HT1A,Ms5HT1B, and Ms5HT7 for in situ hybridization. Using thesereagents, we are investigating the cellular expression patterns ofthe receptors in the AL through immunohistochemistry and insitu hybridization to identify specific AL cells or cell types wherethe receptors may mediate the effects of serotonin.#P114 Poster session III: Cortical chemosensoryprocessing/Receptor genomics and molecular biologyOR37 - receptors: a unique subfamily of olfactory receptorsHeinz Breer, Hoppe Rainer, Zhang Yongquan, Strotmann JörgUniversity Hohenheim, Institute of Physiology Stuttgart,GermanyOlfactory sensory neurons (OSNs) which express the sameodorant receptor (OR) gene are generally widely dispersedthroughout the olfactory epithelium. In contrast, OSNsexpressing a receptor of the OR37 family are assembled in asmall central patch. Besides the unique topographic expressionpattern, OR37 receptors display several other special features. Allmembers of the subfamily share a considerable sequence identity,moreover, they all have an insertion of six amino acids in the thirdextracellular loop. Based on this unique structural feature it isconceivable that the OR37 receptors may be tuned to a definedgroup of ligands. This notion is supported by comparative studiesindicating that orthologous receptors also exist in diversemammalian species, e.g. mouse, dog, primates. Even in humans,this group of receptors exists, with a surprisingly high fraction ofpotentially functional genes, a scenario that is against the generaltrend of pseudogenization for OR genes in humans. Whencomparing the coding sequence of OR37 genes an unexpectedhigh degree of sequence conservation across species borderemerged. The bioinformatic data strongly suggest that the OR37genes apparently are under a negative selective pressure, which isuntypical for OR genes but supports the idea that the OR37receptors are tuned to unique odorous ligands. Also the axonalprojection pattern of OR37 expressing neurons was found to beunique. All neuron populations of the various OR37 subtypesproject their axons onto a small, distinct area of the bulb, whereeach population formed a single glomerulus; all of them located inclose vicinity. During development, from E15 to P0, axons ofdifferent subpopulations terminate in a common area; in a shortpostnatal period (P3) the formation of distinct glomeruli isaccomplished.62 | AChemS Abstracts 2009

#P115 Poster session III: Cortical chemosensoryprocessing/Receptor genomics and molecular biologyPerceptual Decision-Making in the Human Olfactory BrainNicholas E. Bowman, James D. Howard, Konrad P Kording,Jay A. GottfriedNorthwestern University Chicago, IL, USALittle is known about how percepts of odor quality develop in thecontext of olfactory decision-making. Using functional magneticresonance imaging (fMRI) and psychophysical testing weinvestigated the evolution of odor percepts in the human brainand the role of perceptual decision-making in the disambiguationof odor mixtures. A binary odor-mixture set of citral (lemon) andeugenol (clove) was assembled, systematically varying betweenpure citral and pure eugenol, with a total of nine discretemixtures. Participants were instructed to make as many sniffs asneeded to confidently identify which of the two odors was moreprevalent in a given odor mixture trial. After making this binarydecision, subjects made an analog rating on a continuum betweenpure lemon and pure clove, indicating to what extent theyperceived the two odors contributed to the mixture. Psychometricdata from nine subjects show that analog perceptual decisionsreflected the ratio of the pure odorants, and reaction timesincreased with the ambiguity of the odor. At this time, we havecompleted fMRI data collection and analysis from one subject(additional subjects to be presented). Preliminary findingsrevealed increased activation for less ambiguous odor trials inprimary olfactory (piriform) cortex, whereas an inverse patternwas observed in orbitofrontal cortex (i.e., increased activity formore ambiguous trials). These preliminary findings may reveal thedifferent roles that these regions play during perceptualdisambiguation of complex odors. Further analyses willspecifically explore whether fMRI ensemble patterns in piriformand orbitofrontal cortices can predict participants’ perceptualdecisions on a trial-by-trial basis.#P116 Poster session III: Cortical chemosensoryprocessing/Receptor genomics and molecular biologyA novel chemical-informatics method to decode odorreceptor chemical spaceSean M Boyle 1 , Anandasankar Ray 21IGERT, GGB, University of California Riverside, CA, USA,2Entomology Department, University of California Riverside,CA, USALittle is know about how odor receptors can detect a wide varietyof volatile chemicals with high degrees of specificity andsensitivity. The problem is particularly complex due to theextreme diversity in both odorant structures and in receptortypes. We have designed a novel chemical-informatics method toidentify shared molecular features amongst odorants that mayparticipate in binding to specific receptors. This ability to identifyimportant molecular features of odorants was utilized to create anovel-ligand-discovery-pipeline that addresses one of the majorchallenges in olfaction. Functional assays for identifying ligandsof odor receptors limit testing to hundreds of compounds whichrepresents an extremely small fraction (

#P118 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyCharacterizing Olfactory Sub-genome throughCustom MicroarraysXiaohong Zhang, Florencia Marcucci, Dongjing Zou,Stuart FiresteinDept. of Bio. Sci. Columbia University NewYork, NY, USAThe large number of olfactory receptors in rodents necessitateshigh-throughput methods to reveal their expression patterns. Wedesigned a second-generation high-density oligonucleotide arraycontaining all mouse and rat OR genes with different probecoverage. These arrays were approved to be reliable tools tomonitor OR expression. About 1000 mouse ORs and 900 rat ORswere found to be specifically enriched in the olfactory epithelium.It also enabled us to identify the expression profile for the wholeOR family in different tissues and at successive developmentalages. The onset of OR genes at early age and loss of OR genes atold age were found. The temporal expression profiles of all ORswere classified into five interesting patterns, indicating theirpossible behavior-related functions. We also applied our customarray to certain knockout mice and discovered the OR expressionchange, which is proved to be the most promising application ofthe arrays to explore OR regulation.#P119 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyNext Generation Sequencing as a Tool for ComprehensiveVariation Analyses of Human Olfactory Receptor GenesYehudit Hasin 1 , Tsviya Olender 1 , Miriam Khen 1 , Ifat Keydar 1 ,Hans Lehrach 2 , Marcus Albrecht 2 , Bernd Timmerman 2 , DanielReed 3 , Charles J. Wysocki 3 , Jan Korbel 4 , Doron Lancet 11Dept. Molecular Genetics, Weizmann Institute of ScienceRehovot, Israel, 2 Dept. Vertebrate Genomics, Max PlanckInstitute for Molecular Genetics Berlin, Germany, 3 MonellChemical Senses Center Philadelphia, PA, USA, 4 Gene ExpressionUnit, European Molecular Biology Laboratory Heidelberg,GermanyGenomic variation in olfactory receptor (OR) genes most likelyunderlies odorant-specific phenotypes, as attested by reports ofthe respective linkage of OR7D4 and OR11H7P gene variants tothe perception of androstenone and isovaleric acid (Nature449:468 ‘07; PLoS Biol 5:e284, ‘07). Genetic variations that resultin a complete functional knockout of an OR gene in someindividuals are eminent candidates to underlie thresholdphenotypes, as exemplified by OR segregating OR pseudogenes(Nat Genet 34:143 ‘03) and whole-OR deletion alleles (PLoSGenet 4:e1000249 ‘08). Past work has been based on limitedgenomic sequence data and therefore conveys a partial view of theOR variation landscape. We now use the recently introducedNext-Generation DNA sequencing technologies to augment thelist of deleterious and function-modifying OR variations in thehuman genome. As part of this effort we performed Solexa-Illumina deep sequencing of the entire coding region of 96 intactORs (with 250bp flank at each end), in a pool of 21 HapMapindividuals of different ethnic origin. We achieved averagecoverage of 40X per chromosome, thus accurate identification ofrare variations present in the sample. We find a surprising amountof new polymorphisms, some causing premature stop codons ormutating highly conserved amino acids, thus presumablydeleterious. In parallel, we initiate an exploration of novel entire-OR deletion alleles by generating new sequences and scrutinizingpublic data from large-scale sequencing efforts, e.g. the 1000genomes project. Genotyping of current and future instances ofOR gene inactivation events in >400 individuals that we havescored for odorant thresholds may help identify new genotypephenotypecorrelations in human olfaction.#P120 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyOR5D3P, a pseudogene with a functional activity potentialAlex Veithen, Magali Philippeau, Françoise Wilkin, PierreChatelainTecnoScent S.A. Brussels, BelgiumIn humans, it is assumed that 2/3 of the olfactory receptorsubgenome has succumbed to pseudogenisation. Although someOR genes may still be represented by either unaltered andpseudogenic alleles, others seems to be “old” pseudogene sincethe mutation accounting for their pseudogenisation is alreadyrecorded in the ortholog receptor of other primate species. Thehuman receptor OR5D3P corresponds to this latter situation. Itowes its pseudogene status to the lack of a start codon though noother alteration is observed in the rest of its sequence. This ORhas been cloned into an expression vector in fusion with a tagcorresponding to the 20 first amino acids of bovine rhodopsin toallow its expression into a heterologous cell model Using anautomated calcium imaging-based assay, we identified anisylacetate as a ligand for OR5D3P. The deorphanisation was furtherconfirmed by concentration-response analysis performed withboth a reporter gene-based assay and HTRF-based immunoassayallowing direct measurement of cAMP. These results indicate that,despite its pseudogene status, OR5D3P has not accumulated othermutations that would hamper its functionality and suggests that apositive selection pressure has been acting. A possible explanationfor these observations is that the lack of a start methionine couldbe rescued by an upstream exon. Such an approach has alreadybeen proposed for the corresponding chimp ortholog, OR11-140.Further analysis of OR5D3P in the olfactory epithelium remainsto be performed in order to test this intriguing hypothesis.#P121 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyIdentification and characterisation of a carboxylicacid-responding human ORMagali Philippeau, Alex Veithen, Françoise Wilkin, PierreChatelainTecnoScent S.A. Brussels, BelgiumShort chain carboxylic acids constitute an important source ofsweat malodours. Identifying the human olfactory receptors thatrecognize this class of molecules is therefore of interest.Understanding how the associated odour information is processedcould possibly lead to the identification of receptor antagonistsand/or modulators that could efficiently block the perception ofthese offensive smells. Here we describe the deorphanisation ofOR51E1, a receptor that was initially found to respond toisovaleric acid (IVA). The activation by IVA was confirmed bythree different functional assays (i.e. single cell calcium imaging,64 | AChemS Abstracts 2009

luciferase-based reporter gene assay and cyclic AMP measurementwith HTRF-based immunoassay) that all revealed the same rangeof sensitivity of the receptor for IVA (EC50 ~ 30 µM). Astructure-activity relationship study further revealed thatOR51E1 can be activated by carboxylic acids having a linearchain ranging from 4 to 6 carbons. Addition of methyl groupsor introduction of double bonds into the main chain mayhamper the activity of the ligand if these are located close to thecarboxylic function. Unsaturated cyclic carboxylic acids, such ascyclohexanecarboxylic acid, were also found to activate thereceptor whereas the aromatic carboxylic acids were inactive.This work represents one of the most extensive structure activityrelationship analysis performed on a human olfactory receptor.Further studies linking in vitro analysis and genotyping of peopleanosmic to IVA would be required in order to determine theinvolvement of OR51E1 in IVA perception.#P122 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyHigh incidence of charged amino acids in the thirdextracellular loop of olfactory receptors: Linking receptorstructure to olfactory perceptionHadas Lapid 1,3 , Rehan Khan 1 , Tsviya Olender 2 , David Harel 3 ,Ron Naaman 4 , Doron Lancet 2 , Noam Sobel 11Department of Neurobiology, Weizmann Institute of ScienceRehovot, Israel, 2 Department of Molecular Genetics, WeizmannInstitute of Science Rehovot, Israel, 3 Department of ComputerScience and Applied Mathematics, Weizmann Institute of ScienceRehovot, Israel, 4 Department of Chemical Physics, WeizmannInstitute of Science Rehovot, IsraelThe first principal axis of olfactory perception correlates best withthe first principal axis of the physicochemical space [Khan et al.JNS 2007]. We set out to label this physicochemical axis, andidentify receptor attributes that can account for the variance itexplains. We applied principal components analysis to 1338physicochemical descriptors (obtained with Dragon software) of1519 monomolecular odorants. Detailed characterization of thedescriptors that dominated this axis suggested that it reflectsodorant molecular packing. Compact molecules will rarely forman induced dipole in the presence of a local charge or dipole,whereas molecules that are poorly packed will more readilydepolarize. To test for a receptor attribute that can detectvariations in molecular packing, we calculated the probability ofoccurrence of positively charged, negatively charged, polaruncharged and non-polar amino acids at four domains along thesequences of 391 intact human olfactory receptors (HORDE:http://bip.weizmann.ac.il/HORDE). We looked at the first(between TM1 and TM2), second (between TM4 and TM5), andthird (between TM6 and TM7) extracellular loops. We found thatthe variability between proteins was largest in the thirdextracellular loop (F=60, P

following a second stimulation by IBMX/forskolin. We foundthat if stimulations occurred less than 300 seconds apart, thesecond peak was significantly smaller than the first peak in WTOSNs. The second peaks were reduced significantly more in theKO OSNs, providing initial evidence that PMCA-2 contributesnot only to the duration of the transient but also to the durationof adaptation. PMCAs are not just housekeeping enzymes, andwe have shown that they can contribute to the shape of the Ca 2+transient following stimulation.#P125 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyExpression of Canine b-Defensin (CBD103) and OlfactoryMarker Protein (OMP) in the Canine Nasal CavityEdward E. Morrison 1 , Shelly Aono 1 , John C. Dennis 1 , Jishu Shi 21Auburn University Auburn, AL, USA, 2 Auburn UniversityAuburn, AK, USA, 3 Auburn University Auburn, AL, USA,4Kansas State University Manhattan, KS, USACanine b-defensin 103 (CBD103) is a multifunctionalantimicrobial peptidethat also has a strong effect on pigmenttype-switching in domestic dogs. A mutation in the CBD103gene can lead to a black coat, while dogs carrying the wildtypeCBD103 have yellow coat. Olfactory marker protein (OMP) is acytoplasmic protein expressed in mature olfactory receptorneurons. The long term goal of our research is to determinewhether the genetic mutation of CBD103 has any effect onolfactory function and the mucosal immunity protecting theolfactory epithelium in dogs. The objective of this study was todetermine the expression pattern of CBD103 and OMP in thecanine nasal cavity. Using RT-PCR, we have examined theexpression of CBD103 and OMP in the nares/alar fold, ventralnasal concha (rostral and caudal regions), ethmoid labyrinth,olfactory bulb, and vomeronasal organ. It was found thatCBD103 was strongly expressed in the nares/alar fold and rostralventral concha, and OMP was strongly expressed in the ethmoidlabyrinth and olfactory bulb. The strong presence of CBD103 atthe beginning of the nasal cavity indicate that CBD103 may playa critical role in mucosal innate immunity against microbialinfections. Future studies will determine whether CBD103 ispresent in the mucus covering the olfactory epithelium andwhether CBD103 has any effect on the expression of OMPand other functions of olfactory neurons.#P126 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyExperience-Dependent Modulation of Odor Mixture Codingand PerceptionKeng Nei Wu, James D Howard, Jay A GottfriedCognitive Neurology & Alzheimer’s Disease Center,Northwestern University Chicago, IL, USAThe majority of odorous objects encountered in the environmentare composed of dozens, or even hundreds, of volatile molecules.As such, the olfactory system has been designed to optimizedetection of the integrated assembly of odorants (configuralencoding), rather than detection of the parts themselves (elementalencoding). Our study is designed to test the mechanisms by whichodor elements are integrated into perceptual wholes. Usingfunctional magnetic resonance imaging (fMRI) and multivariateanalytical techniques, we investigated how aversive learningmodulates perception and encoding of complex odors.We presented human subjects with seven stimuli: threemonomolecular odorants (A, B, C), three binary mixtures (AB,BC, AC) and one ternary mixture (ABC). Odor-evoked patternsof brain activation to each stimulus were measured before andafter conditioning. During the conditioning phase, one binarymixture (CS+) was repetitively paired with an electric shock whilethe other two (CS-) were not. We tested fMRI correlations ofposterior piriform cortex (PPC) ensemble activity patternsbetween all possible stimulus pairs before and after conditioning.Results from one subject showed an increase in the correlation ofPPC activity patterns between the binary CS+ and its twoelements, but no correlation change between the CS+ and thethird (irrelevant) odorant after conditioning. Conventionalanalysis of the neuroimaging data revealed increased amygdalaactivity during CS+ presentation from pre to post conditioning,consistent with the idea that aversive learning to the CS+ wassuccessfully induced. These preliminary findings suggest thatolfactory learning may induce perceptual and neural fusion ofodor elements into a synthetic whole. Data will be presented fromadditional subjects.#P127 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyEndothelin modulates both short-term kinetics of odorantdetection and long-term cellular population dynamics inolfactory mucosaNicolas Meunier 1,2,3 , Elodie Gouadon 1,2 , Didier Durieux 1,2 , DeniseGrebert 1,2 , Christine Baly 1,2 , Martine Sautel 1,2,3 , Roland Salesse 1,2 ,Monique Caillol 1,2 , Patrice Congar 1,21INRA, UMR1197 Neurobiologie de l’Olfaction et de la PriseAlimentaire, Récepteurs et Communication Chimique Jouy enJosas, France, 2 Université Paris-Sud, UMR1197 Orsay, France,3Université de Versailles Saint-Quentin Versailles, FranceIn search of regulatory factors of the olfactory mucosa (OM),we have previously shown that endothelin is locally matured inthe OM and that olfactory sensory neurons (OSNs) expresspreferentially ET B receptors, while ET A receptors are ratherpresent in non-neuronal OM cells (nNCs). Using EOGrecordings, we first observed that a direct application ofendothelin (ET-1) could modulate the kinetics of odorantdetection while the amplitude of the response was unchanged.As this effect was blocked by ET A antagonist, we examined themodulation of GAP junctions on nNCs by electrical stimulationof primary cultured cells of OM by calcium imaging. ET-1 couldlimit the propagation of electrical stimulation in nNCs similarlyto a known GAP junction antagonist. Thus, the observedmodulation of odorant detection kinetics in EOG may be relatedto a change of electrical coupling between nNCs, due to the actionof ET-1 on ET A receptors. In addition to its vasoactive effect, theendothelin system is mainly known to act on cell populationdynamics. While a serum deprivation leads to a massive decreaseof OSNs in primary cultures of OM, a treatment with ET-1rescued part of the cellular death through both ET AB receptors.Interestingly, we observed that an ET B receptors-deficient straindisplayed a decreased sensitivity to odorants detected by EOG.Endothelin has thus at least a dual role on the OM. It canmodulate the kinetics of odorant detection, but also affects thesurvival of OSNs on a longer term.66 | AChemS Abstracts 2009

#P128 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyNeuroanatomical correlates of olfactory functionJohannes Frasnelli 1, 2 , Johan N Lundstrom 2, 3 , Julie A Boyle 2 ,Jelena Djordjevic 2 , Robert J Zatorre 2 , Marilyn Jones-Gotman 21CHU Ste.-Justine Montreal, QC, Canada, 2 MNI Montreal, QC,Canada, 3 Monell Chemical Senses Center Philadelphia, PA, USAIn recent years, objective whole-brain techniques (voxel-basedmorphometry, VBM) have become available that allowsegmentation of brain structures into grey matter, whitematter and cerebrospinal fluid. In the present study we used themto investigate the correlation between individual grey matterthickness and olfactory function. Forty-four subjects (25 women,19 men) underwent extensive olfactory testing including odoridentification, detection thresholds, intensity discrimination andquality discrimination. The behavioral results and subjects’anatomical MRI scans were analyzed using two MNI in-houseprograms CIVET and Surfstat. A global analysis demonstratedthat general olfactory function was correlated with grey matterthickness in and around the right central sulcus and the rightparacentral lobule. Moreover, a predicted regions analysisdemonstrated a correlation with an area around the right olfactorysulcus. Of the individual olfactory tasks, odor discrimination wascorrelated with cortical thickness of right insula, right precentralgyrus, right superior parietal lobule and right parietal lobule.Odor identification was correlated with cortical thickness in theright superior temporal lobule, with an interaction with subjects’sex in occipital regions and the entorhinal cortex. These resultsindicate that performance on individual olfactory tests is reflectedin brain anatomy.#P129 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyMechanisms of constitutive and ATP-evoked release ofATP from neonatal mouse OE storesSebastien Hayoz, Colleen C HeggDepartement of Pharmacology and Toxicology, Michigan StateUniversity East Lansing, MI, USAATP, an important extracellular signaling molecule, is releasedconstitutively and actively in many cell types. We previouslyshowed the release of ATP from basally-situated ATP stores viapurinergic receptor stimulation and vesicular fusion. Here, wefurther characterized the mechanisms of constitutive and evokedATP release. Using confocal imaging of endogenous ATPfluorescently-tagged by quinacrine, the % ATP release wasmonitored in the absence (control, constitutive) or presence(evoked) of exogenous ATP (50 µM). In control conditions, ATPrelease occurred in the basal, middle and apical OE (34±2, 38±3,32±1 % basal fluorescence (%Fo), respectively). Exogenous ATPsignificantly induced release of endogenous ATP in basal OE(18±1 %Fo; p

#P131 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyDifferences in Matrix Metalloproteinase-2 ExpressionFollowing Two Olfactory Injury ModelsSteve R. Bakos 1 , James E. Schwob 2 , Richard M. Costanzo 11Virginia Commonwealth University School of MedicineRichmond, VA, USA, 2 Tufts University School of Medicine Boston,MA, USAWe previously reported that matrix metalloproteinase-9 (MMP-9),an enzyme involved in extracellular matrix regulation, is elevatedfollowing olfactory nerve transection (NTx) and methyl bromidegas (MBr) injuries. In this study, we examined MMP-2. We usedWestern blot methods to measure the levels of MMP-2, GAP-43and olfactory marker protein (OMP) in the bulb of mice atdifferent time points following NTx and MBr injury. GAP-43and OMP were used as markers to detect immature and matureolfactory neurons. In control animals, MMP-2 levels were notobserved. After NTx, MMP-2 expression levels increased withinhours and a large peak was observed at day 7. After MBrexposure, MMP-2 expression remained near control levels.Both GAP-43 and OMP decreased soon after NTx, reflectingdegeneration of axon fibers and deinnervation of the bulb. Therewas a large increase in GAP-43 observed between recovery day 3and 7, indicating regeneration and the growth of new axon fibersreinnervating the bulb. OMP levels began to increase around day10, reflecting the maturation of olfactory neurons. GAP-43 andOMP levels decreased at a slower rate after MBr injury and didnot increase until recovery day 40, indicating reinnervation of thebulb occurred later with MBr than for NTx. This is the first studyto compare changes in MMP-2 levels after both NTx and MBrinjuries. These findings suggest that MMP-2 may be associatedwith deinnervation and reinnervation processes in the olfactorybulb following NTx but not MeBr (in contrast to MMP-9),perhaps serving as a transition event signifying a lesion-specificswitch from degradation to the recovery of olfactory neurons.#P132 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyIdentification of Taste Bud-Associated GenesBryan D Moyer 1 , Peter Hevezi 2 , Na Gao 1 , Min Lu 1 , FernandoEcheverri 1 , Bianca Laita 1 , Dalia Kalabat 1 , Hortensia Soto 1 , AlbertZlotnik 2 , Mark Zoller 11Senomyx, Inc. San Diego, CA, USA, 2 Univeristy of California atIrvine Irvine, CA, USAA systematic and comprehensive genome-wide screen wasconducted to identify taste bud-associated genes. Taste buds andnon-gustatory lingual epithelium were collected using lasercapture microdissection and isolated RNAs were hybridized tomicroarrays to generate an expression database of over 2,300 tastebud-associated genes, including ~200 genes predicted to encodemulti-transmembrane proteins with no known function in taste(ISOT XV Poster #132; p88-89, 2008). An important first step inelucidating the function of these gene products in gustation is toidentify the specific cell types in which they are expressed. Usingdouble label in situ hybridization analyses, we identified genesexpressed in sweet, bitter, and umami cells (TRPM5-positive) andsour cells (PKD2L1-positive). CALHM1 (calcium homeostasismodulator 1), a component of a novel calcium channel, MCTP1(multiple C2 domains, transmembrane 1), a calcium-bindingtransmembrane protein, and ANO7 (anoctamin 7), a member ofthe recently identified calcium-gated chloride channel family wereexpressed in TRPM5 cells. These proteins may modulate calciumsignaling stemming from sweet, bitter, and umami receptoractivation. SV2B (synaptic vesicle glycoprotein 2B), a regulator ofsynaptic vesicle exocytosis, was expressed in PKD2L1 cells,supporting the role of exocytic neurotransmitter release in thiscell population. In addition, IKBKAP (inhibitor of kappa lightpolypeptide gene enhancer in B-cells, kinase complex-associatedprotein), a gene mutated in the disease familial dysautonomia thatresults in loss of taste buds was specifically expressed in PKD2L1cells. Elucidating the functions of these and other taste budassociatedgenes in gustation will advance our understanding oftaste biology in normal and diseased states.#P133 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyFunctional characterization of two fatty acid activated GPCRsexpressed in the mammalian gustatory systemHan Xu 1 , Jason Montez 2 , Stephen Gravina 2 , Mark Dewis 2 ,Tian Yu 1 , Bhavik P. Shah 1 , Timothy A. Gilbertson 11Department of Biology & The Center of Advanced Nutrition,Utah State University Logan, UT, USA, 2 International Flavors &Fragrances Union Beach, NJ, USAGiven that the epidemic of obesity appears to be driven, at least inpart, through an increase in dietary fat intake, it has becomeincreasingly important to identify the mechanisms the body usesto recognize dietary fat. Recently, we have identified a number offatty acid (FA) activated G protein coupled receptors (GPCRs)that we hypothesize play a role in the initial recognition of freefatty acids, the prototypical fat stimulus, in the oral cavity. Two ofthese FA-GPCRs, GPR120 and GPR84, are highly expressed inthe taste and somatosensory systems and are activated by longchain and medium chain fatty acids, respectively. To characterizethese receptors in greater detail and explore the interaction ofthese receptors with another putative FA receptor, CD36, we havedesigned cell lines that inducibly express either GPR84+G qi9 orGPR120+G 16 with and without CD36. Using FLIPR-basedassays, we show that these cell lines expressing GPR84+G qi9 orGPR120+G 16 alone respond with appropriate specificity to theircognate ligands. Cells expressing GPR84 respond to the mediumchain saturated fatty acid, capric acid (5-40 µM), but not to a longchain unsaturated fatty acid (LCFA), linoleic acid, over a similarconcentration range. Conversely, cells expressing the LCFAspecificreceptor, GPR120, respond to linoleic acid, but not capricacid. Both receptors respond in the expected concentration ranges.Currently, we are using ratiometric (Fura2) calcium imaging toexplore these receptors in greater detail and determine the effectthat coexpression of CD36 has on the specificity and sensitivityof FA signaling in these cell lines.68 | AChemS Abstracts 2009

#P134 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biology#P136 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyGenetic and Molecular Basis of Individual Differencesin Human Umami Taste PerceptionNoriatsu Shigemura 1 , Shinya Shirosaki 1 , Keisuke Sanematsu 1 ,Yoko Ogiwara 1,2 , Misako Kawai 1,3 , Ryusuke Yoshida 1 , YuzoNinomiya 11Sect Oral Neurosci, Grad Sch Dental Sci, Kyushu Univ Fukuoka,Japan, 2 External Scientific Affairs Dept, Ajinomoto Co. Inc.Tokyo, Japan, 3 Inst Life Sci, Ajinomoto Co. Inc. Kawasaki , JapanDuring periods of human expansion into new environments,recognition of amino acids through taste may have conferredan important selective advantage. Umami taste is elicited bymonosodium glutamate (MSG), and is one of five basic tastequalities that plays a key role in intake of amino acids. Aparticular property of umami is the synergistic potentiation ofglutamate by purine nucleotide monophosphates (IMP, GMP).A heterodimer of a G protein coupled receptor, TAS1R1 andTAS1R3, is proposed to function as its receptor. Polymorphicsites and single nucleotide polymorphism (SNP) frequencies inthese genes vary widely in human populations. If thediversification of these genes reflects adaptation to changingnutritional environments, the genetic variations of TAS1R1 andTAS1R3 may show correlations with differences in umamisensitivity and affect the receptor function. Here we showed theassociation between recognition thresholds for umami substancesand genetic variations in human TAS1R1 and TAS1R3, using tastetests and a heterologous expression system. This result suggeststhat natural selection on TAS1R1 and TAS1R3 alleles may havebeen particularly important, at least in part, in human evolution.#P135 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyIdentification of the Interaction site for Gymnemic acid at thesweet taste receptor T1R2+T1R3Keisuke Sanematsu 1,2 , Noriatsu Shigemura 1 , Masafumi Jyotaki 1 ,Seiji Nakamura 2 , Toshiaki Imoto 3 , Yuzo Ninomiya 11Section of Oral Neuroscience, Gracuate School of Dental Science,Kyushu University Fukuoka, Japan, 2 Section of Oral andMaxillofacial Oncology, Gracuate School of Dental Science,Kyushu University Fukuoka, Japan, 3 Division of IntegrativePhysiology, Department of Functional, Morphological andRegulatory Science, Tottori University Yonago, JapanGymnemic acid (GA) is a triterpen glycoside that is isolated fromthe plant Gymnema sylvestre. It is known that GA selectivelysuppresses taste responses to various sweet compounds withoutaffecting responses to salty, sour and bitter substances. Sweetsuppressingeffect of GA is specific to humans and chimpanzees,but not to rodents. It has also been shown that the sweetsuppressingeffect of GA is diminished by rinsing the tongue withg-cyclodextrin (CD). In order to examine whether GA directlyinteract with T1R2+T1R3, we used the sweet receptorT1R2+T1R3 assay in transiently transfected HEK293 cells.Similar to previous studies in humans and mice, GA (0.1 mg/ml)inhibited the [Ca 2+ ] i responses of cells heterologously expressinghT1R2+hT1R3 to SC45647, saccharin and D-tryptophan. Thesweet-suppressing effect of GA rapidly disappeared after rinsingthe cells with 1% g-CD. The mouse pair (mT1R2+mT1R3) wasnot sensitive to GA. One mismatched pair (hT1R2+mT1R3)behaved like the fully mouse heterodimer, showing no sensitivityto GA. These results demonstrate that hT1R3 is required for GAsensitivity. To identify the interaction site for GA, we examinedthe responses of the mouse/human chimeras of T1R2 and T1R3.The results suggest that the sensitivity to GA depends mainly onthe transmembrane region of human T1R3.P O S T E R SGenetic mutations and bitter taste sensitivity to foursubstancesStephen Wooding 1 , Natacha Roudnitzky 2 , Claudia Batram 2 , JennyStehr 2 , Marcel Winnig 2 , Christina Kuhn 2 , Wolfgang Meyerhof 21University of Texas Southwestern Medical Center Dallas, TX,USA, 2 German Institute of Human Nutrition Nuthetal, GermanyBitter taste perception is initiated by TAS2R receptors, proteinsexpressed in taste buds. Mutations in the TAS2R genes can causevariation in bitter taste sensitivity. We investigated the effects ofmutations in three genes and their effects on the bitter perceptionof two artificial sweeteners (saccharin and acesulfame K) and twomarker substances, salicin and denatonium benzoate. Ourfindings support earlier evidence that mutations in the TAS2R43and TAS2R44 genes cause variable bitter perception of saccharin.We found that the same mutations account for variation in thebitterness of acesulfame K. In addition, we found that variation inthe TAS2R45 gene may be important in the bitter perception ofthese substances. Finally we found that these mutations differ infrequency among worldwide populations.#P137 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyThe role of the visual cortex in olfactory processing:an rTMS studyJohan N. Lundstrom 1,2 , Michael Waterston 3 , Jahan Jadauji 3 ,Christopher C. Pack 3 , Jelena Djordjevic 31Monell Chemical Senses Center Philadelphia, PA, USA,2Department of Psychology, University of PennsylvaniaPhiladelphia, PA, USA, 3 Montreal Neurological Institute,McGill University Montreal, QC, CanadaIt has become clear that crossmodal connections modulateunimodal perception to a larger extent than previously thought.An example is the often-reported but seldom-discussed findingfrom olfactory imaging experiments that higher-order odor tasksactivate cortical areas commonly associated with visualprocessing. We are currently exploring this phenomenon usingrepetitive transcranial magnetic stimulation (rTMS), a techniquethought to be capable of upregulating neuronal activity instimulated areas, as demonstrated by improved low contrastdetection following primary visual cortex (V1) stimulation.Through stimulation of V1, we are investigating the visualsystem’s impact on olfactory processing. In a within-groupdesign, either V1 (experimental condition) or the vertex (controlcondition) is stimulated while measures of olfactory identification,Abstracts | 69

supra-threshold discrimination, and peri-threshold intensitydiscrimination performance are obtained. Visual acuity isadditionally measured to verify successful stimulation of V1.Though a limited number of participants have been tested to date,initial analyses indicate that rTMS stimulation of V1 primarilymodulates supra-threshold discrimination and peri-thresholdintensity discrimination performance and has less impact onolfactory identification performance. These initial results indicatethat the primary visual cortex is capable of modulating higherorderolfactory processing.#P138 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyTAS1R1-intronic SNP Associations with Liking for DietarySources of Glutamate and for Orosensory IntensityShristi Rawal 1 , Margaret R. Wallace 2 , John E. Hayes 3 ,Linda M. Bartoshuk 4 , Taimour Y. Langaee 5 , Andrew Sholudko 1 ,Valerie B. Duffy 11Allied Health Sciences, Univ of CT Storrs, CT, USA, 2 MolecularGenetics & Microbiology, Univ of FL Gainesville, FL, USA,3Ctr Alcohol & Addiction, Brown Univ Providence, RI, USA,4Dentistry, Univ of FL Gainesville, FL, USA, 5 CtrPharmacogenomics, Univ of FL Gainseville, FL, USABackground: Gene products of the TAS1R family formheterodimeric receptors that appear to mediate umami(hT1R1+hT1R3) and sweet (hT1R2+hT1R3) sensations (Li et al,2002). Limited information exists on the contribution of TAS1R1variation to functional differences in taste perception, althoughexonic variation has been described in vivo (Kim et al, 2006).Methods: DNA samples from 90 healthy adults were collectedfrom whole bloods, isolated and genotyped for TAS1R1 intronicSNP (rs17492553) by TaqMan genotyping. Results: Similargenotype frequencies were seen in our sample (33% CChomozygous for major allele, 41% were heterozygous, 26%TT homozygous for minor allele) to reference frequencies forEuropean-Americans (50%, 21%, and 29%, respectively). Usingthe sensory and hedonic forms of the general Labeled MagnitudeScale, subjects rated the intensity of: liking and taste quality ofsampled foods/beverages, prototypical tastants painted onfungiform and circumvallate papilla and tasted with the wholemouth; and 25% ethanol painted on the tongue tip. In analysis ofcovariance controlling for age, sex and intensity of tones as across-modal standard, CC adults reported greater liking forsampled soy sauce and white grapefruit juice (sources ofglutamate) than did TT adults, with concurrent increases insourness ratings for the juice. As expected, this SNP failed toexplain differences in liking and sweetness of sampled sweetfoods. However, this SNP explained intensity differences in thespatially-applied ethanol probe and tastants. The TT adults and, insome cases heterozygous adults, reported lower intensities thandid the CC adults. Conclusions: These results support a role ofTAS1R1 SNPs in response to glutamate and further suggest theircontribution to general variability in orosensory intensity.#P139 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyKey amino acid residues involved in multi-point bindinginteractions of sweet protein, brazzein, with the T1R2-T1R3human sweet receptorFariba Assadi-Porter 1 , Emeline L Maillet 2 , James Radek 1 ,John L Markley 1 , Marianna Max 21University of Wisconsin Madison, WI, USA, 2 Mount SinaiSchool of Medicine New York, NY, USABrazzein protein tastes sweet to humans through activation of thesweet sensing receptor heterodimeric GPCR composed ofmonomers T1R2 and T1R3. Brazzein’s sweetness depends onboth its three-dimensional structure and on distributed sites in itssurface chemistry as we have shown by structural, dynamic andfunctional assays (both human psychophysical taste assays andfunctional heterologous expression assays) of wildtype andmutant brazzein proteins. Here we show data from ourinvestigation of three “sweetness” sites on brazzein: loop 43 (Site1); the N and C termini and the proximal Glu36 residue (Site 2);and loop 9-19 (Site 3). We have found that the presence of basicresidues in Site 1, and acidic residues in Site 2 play significant rolesfor brazzein’s sweet taste. We also find that position 54 (Site 2)requires a bulky side chain rather than one with hydrogenbonding potential for sweetness. We determined that properdisulfide bond formation in loop 9-19 (Site 3) is essential forsweetness. We also investigated several areas of the sweet receptorthat modify the brazzein response. We confirmed the involvementof the CRD of T1R3 in brazzein activity by identifying an acidicresidue that is essential for brazzein activity. We alsodemonstrated that the T1R2 VFTM participates in the ability ofbrazzein to activate the sweet receptor, suggesting that it tooforms a point of interaction for brazzein. We have assessed severalmodels for the brazzein binding site within the extracellulardomains of T1R2/T1R3 receptor by mutating charged and polarresidues within the small-molecule binding clefts as well asproximal residues in the interface between and along the backs ofthe T1R2 and T1R3 monomers and characterizing the resultingmutant receptors by a functional calcium mobilization assay.#P140 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyOrbitofrontal lesions and hypersensitivity to olfactory stimuliJulie A. Boyle, Marilyn Jones-GotmanMontreal Neurological Institute, McGill University Montreal,QC, CanadaHypersensitivity to odors has previously been reported in patientswith adrenal cortical insufficiency (Henkin and Bartter, 1966).However, little is known regarding other clinical causes ofhypersensitivity. We studied the olfactory profile two neurologicalpatients complaining of increased sensitivity to olfactory stimuli.Patient 1, MP, is a 40 year old right handed man with multiplecerebral contusions in the frontal, including the bilateralorbitofrontal (OFC) and left temporal (TL) cortices. Detectionthresholds for phenyl ethyl alcohol (PEA) were assessedmonorhinally using an ascending staircase method. MP was ableto detect our weakest dilution of PEA (i.e. 16 th dilution step) ineach nostril. He has tested significantly above his neurologicallynormal peers whose mean sensitivity for PEA has been reportedto range between the 6 th to the 7 th dilution (Deems and Doty,70 | AChemS Abstracts 2009

1987). MP’s olfactory discrimination (Zatorre and Jones-Gotman,1990) score was 16 out of 16 on both nostrils. UPSIT score wasconsidered to be within normal range. Patient 2, CG, is a 59 yearold right handed woman with bilateral OFC and TL lesions. CGhad an increased sensitivity to PEA (detected the 16 th dilutionstep) compared to aged matched controls, performed in the 99%percentile of all age groups on the UPSIT and got 16 correct outof a possible 16 on each nostril on the discrimination task. Thecurrent findings for threshold and discrimination were consideredto be significantly higher than expect from age matchedneurologically normal patients. Further, patients with frontal andTL damage are known to have deficits in odor identification anddiscrimination, as opposed to the heightened abilities observed inMP and CG. Additional analyses will be undertaken to assess theoverlap in lesions of these two patients#P141 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyStructural requirements for bitter taste receptor activationMaik Behrens 1 , Anne Brockhoff 1 , Giovanni Appendino 2 ,Wolfgang Meyerhof 11Dept. Molecular Genetics, German Institute of Human NutritionPotsdam-Rehbruecke Nuthetal, Germany, 2 Dipartimento diScienze Chimiche, Università del Piemonte, Orientale, Alimentari,Farmaceutiche e Farmacologiche Novara, ItalyAt present, for 12 of the 25 human bitter taste receptors(hTAS2Rs) activating bitter substances were identified. In general,hTAS2Rs are activated by multiple different agonists. However, asall hTAS2Rs exhibit a unique agonist response profile, thisobservation is not simply caused by a reduced agonist-specificity.The responsiveness of hTAS2Rs to multiple low-affinity agonistsis in sharp contrast to other GPCR-families with few, or evensingle, high-affinity agonists indicating differently organizedbinding pockets. With the present study we investigated whichamino acid residues of hTAS2Rs are involved in agonistinteractionand how binding pockets of hTAS2Rs might beorganized. We chose the broadly tuned receptor hTAS2R46 forthis study because a number of closely related receptors withdistinct agonist interaction profiles are available, and thus, allowfocusing on few amino acid differences responsible for agonistselectivity. Guided by differences in amino acid sequences and insilico modeling studies, we identified hTAS2R46 residues, whichare likely responsible for agonist selectivity and subjected thecorresponding positions to point mutagenesis. Calcium imaginganalyses of receptor mutants were performed to assess thefunctional consequences of amino acid exchanges. This approachenabled us to identify a number of positions that contribute tovariable extents to the hTAS2R46-specific agonist profile.Introduction of these residues into the receptors hTAS2R43, -44,and -50 resulted in the transfer of hTAS2R46 agonist profile and,in part, pharmacological properties onto those receptors. Ourfindings allow the conclusion that the investigated hTAS2Rspossess, analogous to other GPCRs, a single, positionallyconserved binding pocket accommodating the various testedagonists.#P142 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyImmunohistochemical Analysis of Human Fungiform PapillaeLuba Dankulich-Nagrudny 1 , Nancy Rawson 1,2 , Frank Kim 1 ,Paul A. S. Breslin 11Monell Chemical Senses Center Philadelphia, PA, USA,2WellGen New Brunswick, NJ, USALittle data are available analyzing the cellular organization andimmunocytochemical characteristics of human fungiform papillae.The basic cellular organization is similar to that of other mammalswith respect to the types of cells and the number of cells within ataste bud. Taste buds contain two types of cells that are known todirectly participate in taste detection: chemosensory transductionreceptor(Type II) cells, and presynaptic (Type III) cells. Receptorcells express G protein- coupled taste receptors and respond tosweet, bitter and umami taste stimulation. With antibodylabeling, we find that the immunoreactivity for several tastetransduction molecules was seen consistently in cells withinfungiform papillae, including: Gustducin, Gg13, PLC(phospholipase C ) and IP3R3 (Inositol triphosphate receptortype 3). Cells with neuronal characteristics were also observed,based on immunostaining for synaptic vesicle marker SNAP-25,Syntaxin and PGP9.5 (Protein Gene Product 9.5), which weredetected in fibers and/or cell membranes within the taste bud.Cells immunostained with neural cell adhesion molecule NCAM,also reported to be present in Type III cells, were also detected.Double-labeling immunocytochemistry for Gustducin and IP3R3,PGP9.5 and Gg13 indicated separate cell populations. Theseresults strongly suggest separate populations of synapticallycommunicating cells and taste-receptor expressing cells in humanfungiform papillae.#P143 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologySubtypes of T Lymphocytes in Healthy HumanFungiform PapillaePu Feng, Paul A.S. BreslinMonell Chemical Senses Center Philadelphia, PA, USAWe previously identified the key immune cells (i.e. lymphocytes,macrophages, dendritic cells and Langerhans cells) in humanfungiform papillae (FP). Of these cells, CD4 T cells were one ofthe most predominant types. CD4 T cells are divided to Th1 andTh2 cells based on the cytokines they produce. They also expressdifferent surface markers: e.g., CCR5 for Th1 and CCR4 for Th2cells. Th1 cells are more related to inflammation and cytotoxicactivities, while Th2 cells are more related to allergy, IgEproduction, and anti-inflammatory reactions. T-cells generallyconsist of a mixture of naïve (CD45RA+, having no immunefunction) and memory (CD45RO+, with capability of immunefunction) subsets. After antigen stimulation, some naïve T cellstransition to memory cells and activated cells. Most T cells expressthe receptor (TCR) alpha/beta, but the TCR gamma/delta subsetis relatively enriched within epithelia and plays a special role inmucosal immune. In this study, we studied the different T-cellsubtypes in human FP by examining the surface antigensassociated with T cell functions and activation viaimmunohistochemistry. Biopsies of human FP were taken fromthe anterior tongue. Interestingly, we found that CD45RO+memory cells were the principal T cells in FP, while CD45RA+P O S T E R SAbstracts | 71

naïve T cells were uncommon. This may reflect the activation ofnaïve T cells at the site of exposure to repeated antigen stimulationTh1 cells were more predominant in FP than Th2 T cells. Thissuggests that the local immune response in the gustatory system isTh1-type biased. Few gamma/delta TCR T cells were in FP. Thisstudy provides background for understanding inflammatoryresponses in gustatory tissue and clinical interactions between theimmune and gustatory systems.#P144 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyNeutrophil infiltration impairs peripheral taste functionLiqiao Shi, Lynnette McCluskeyMedical College of Georgia Augusta, GA, USAUnilateral chorda tympani (CT) nerve sectioning induces rapidfunctional changes in the neighboring, intact population of tastereceptor cells. Within one day after contralateral sectioning,neural responses to sodium are specifically decreased. We proposethat these injury-induced changes in taste function are mediatedby leukocytes. Neutrophils invade the taste system within hoursof injury, in parallel with decreased responses to sodium in theintact CT nerve. Dietary treatments that amplify the neutrophilresponse extend the functional impairments. Importantly,depletion of neutrophils restores normal taste responses. In thecurrent study, we tested the hypothesis that neutrophil infiltrationin the absence of nerve sectioning also impairs sodium tastefunction. Specified pathogen-free (SPF) Sprague-Dawley ratsreceived injections of the endotoxin, lipopolysaccharide (LPS; 10µg in 10 µl sterile PBS), to the ventral tongue. This treatmentsignificantly increased the number of neutrophils in the anteriorfungiform field. Neurophysiological recordings from the CTnerve were performed at 24 hr post-injection. CT responses toNaCl and sodium acetate were suppressed in LPS-injected vs.PBS-injected rats. In contrast, neural responses to non-sodiumstimuli did not differ between groups. These findings indicate thatneutrophils have a negative impact on sodium taste function,whether they are elicited by nerve injury or endotoxin. Wesuggest that neutrophils responding to tissue damage, nerveinjury, or bacterial infection release molecules that selectivelydownregulate sodium channel expression and/or function in tastereceptor cells.#P145 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyMouse taste buds express vesicular glutamate transportertype 2Leslie Stone 1,2 , Catherine Anderson 1,2 , Daniel Goldberg 1,2 ,Sue Kinnamon 1,21Dept. Biomedical Sciences, Colorado State University, FortCollins Colorado , 2 Rocky Mountain Taste & Smell Center,University of Colorado, Aurora, ColoradoVarious potential neurotransmitters are reported in taste buds, buttheir precise roles are mostly unknown. Previously, we presentedevidence that ATP is necessary for communication between tastebuds and taste nerves. In this study, we investigated the potentialrole of glutamate as a neurotransmitter by analyzing vescicularglutamate transporter (VGLUT ) expression in peripheral tastetissue. VGLUTs are a family of 3 proteins that load glutamateinto synaptic vesicles; the presence of VGLUTs in a cell ispresumptive evidence that it is glutamatergic. Previous studiessupport the idea that glutamate may be a transmitter in taste buds.Various metabotropic glutamate receptors (mGluRs) areexpressed in type II taste cells and in nerve fibers associated withtaste buds. Some taste cells exhibit robust immunoreactivity forglutamate. To further explore whether glutamate might be atransmitter in taste buds, we used immunocytochemistry andRT-PCR for VGLUTs on tissues obtained from mousecircumvallate papillae. Surprisingly, we found VGLUTexpression in nerves innervating the taste buds, but not in tastecells themselves. Immunocytochemical analysis shows that theVGLUT2+ nerve fibers are closely associated with gustducinexpressingtype II cells. To test whether taste cells might expresslow levels of VGLUTs, we performed RT-PCR of pooled mousecircumvallate taste buds. No VGLUT PCR products weredetected in RNA collected from taste buds, although there wasrobust expression of all VGLUT isoforms in the brain. Together,our results suggest that nerve fibers associated with taste buds arecapable of releasing glutamate. This may indicate that glutamateserves as an intragemmal modulator of taste bud function ratherthan as a means of transmission of information from taste cells tonerve fibers.#P146 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologySerotonin Inhibits ATP Secretion in Mouse Taste BudsYijen A. Huang 1 , Stephen D. Roper 1,21Department of Physiology & Biophysics, Miller School ofMedicine, University of Miami Miami, FL, USA, 2 Program inNeuroscience, University of Miami Miami, FL, USADuring taste stimulation, Receptor (Type II) cells secrete ATP.ATP, in turn, activates adjacent Presynaptic (Type III) cells torelease serotonin (5-HT) and norepinephrine (NE) (Huang et al, JNeurosci, 2008). These interactions indicate feed-forward, cell-tocellcommunication within taste buds. Here, we tested whether 5-HT and NE exert feedback onto Receptor cells. We measuredATP secretion from isolated taste buds and from Receptor cellsusing biosensors (CHO cells stably transfected with P2X2/P2X3receptors and loaded with the calcium-sensitive dye, Fura-2;Huang et al, PNAS, 2007). As previously shown, taste budsisolated from mouse vallate papillae secreted ATP in response tostimulation with tastants (mixture of cycloheximide, 10 µM;saccharin, 2 mM; denatonium, 1 mM; SC45647, 0.1 mM). Bathapplied5-HT (10 nM) abolished taste-evoked ATP secretion fromisolated taste buds. 5-HT1A receptor agonists, 8-OH-DPAT (10nM) or BP554 (10 nM), similarly inhibited taste-evoked ATPsecretion. Finally, paroxetine (100 nM), a 5-HT reuptake inhibitor,reduced ATP secretion. In contrast, taste-evoked ATP secretionwas elevated ~2X by methysergide (10 nM), a 5-HT1,2 receptorantagonist, and by WAY100635 (10 nM), a 5-HT1A receptorantagonist. We did not detect any actions of NE on Receptor cells,either positive or negative (Huang et al, J Neurosci, 2008). In sum,these findings indicate that during taste stimulation, 5-HTreleased from Presynaptic (Type III) cells exerts negative feedbackonto Receptor cells by activating 5HT1A receptors and reducingATP secretion. This suggests that 5-HT plays an important role inmodulating peripheral taste responses.72 | AChemS Abstracts 2009

#P147 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyExpression of an Inwardly-Rectifying Potassium Channel(ROMK) in Mouse Glial-like Taste CellsGennady Dvoryanchikov 1 , Michael Sinclair 2 , Nirupa Chaudhari 1,21Department of Physiology and Biophysics, University of MiamiMiller School of Medicine Miami, FL, USA, 2 Program inNeurosciences, University of Miami Miller School of MedicineMiami, FL, USACells in taste buds are closely packed with little extracellularspace. Tight junctions and other barriers further limitpermeability and may result in the buildup of K + during actionpotentials. In many tissues, inwardly-rectifying K channels suchas the Renal Outer Medullary K (ROMK) channel help toredistribute K + . ROMK is an inwardly rectifying ATP-sensitiveK channel, derived from the kir1.1 (kcnj1) gene. Using RT-PCR,we defined several splice variants of ROMK in mouse kidney, andreport here the expression of a single one of these splice variants,ROMK2, in a subset of mouse taste cells. Using qRT-PCR, wefound ROMK2 mRNA is expressed in taste buds in the followingorder of abundance: vallate > foliate >> palate >> fungiform.Immunocytochemistry revealed that the ROMK protein followsthe same pattern as mRNA, and is essentially undetectable infungiform taste buds. ROMK is localized to the apical tips of asubset of taste cells (~8.5+/-2.5 cells/vallate tastebud). Usingtissues from PLCb2-GFP and GAD-GFP transgenic mice, weshow that ROMK is not expressed in PLC 2-expressing typeII/Receptor cells or in GAD-expressing type III/Presynaptic cells.Thus, immunocytochemical data suggest that ROMK expressionis limited to a subset of glial-like type I cells. Single-cell RT-PCRconfirms this interpretation: ROMK2 mRNA was detected in23% of NTPDase2-expressing cells, but not in either PLCb2- orSNAP25-expressing taste cells. We propose that in taste buds,ROMK in supporting type I cells may serve a homeostaticfunction, excreting excess K + through the apical pore, andallowing excitable taste cells (types II and III) to maintain ahyperpolarized resting membrane potential.#P148 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyCortical Processing of Learned Aversive Odors in Awake RatsChien-Fu F Chen 1,3 , Donald A Wilson 1,21Nathan Kline Institute Orangeburg, NY, USA, 2 NYU School ofMedicine New York, NY, USA, 3 The University of OklahomaNorman, OK, USAMost naturally occurring odors are complex mixtures. Thesemixtures are hypothesized to be synthesized into odor objectsthrough activity of olfactory cortical circuits. Work inanesthetized rats has demonstrated that neurons in the anteriorpiriform cortex discriminate between mixtures and theirindividual components. Furthermore, it has been shown thatcortical odor processing is experience-dependent, with familiarityleading to enhanced discriminability of odorants. However, thereis still limited data on cortical processing of odors in awakeanimals. The present experiment had two primary goals. First,compare activity of neurons in the anterior piriform cortex ofawake rats to those in anesthetized rats in response to complexmixtures and second, examine how aversive conditioning canaffect that processing. Long-Evans rats were chronicallyimplanted with movable wire bundles aimed at the anteriorpiriform cortex. Responses of single-units to individual odorantsand mixtures were tested. Odors were randomly presented fromthe top of the recording chamber to mimic natural odor plumes.Following several days of recording, one odor was chosen as theconditioning odor in an odor aversion conditioningparadigm. Unit data was recorded during the conditioning trialsand for several days post-training. The electrode was moved overtime to sample additional cells. Preliminary results (n = 148 units)suggest that 35% of the units responded to any one odor or odormixture, which is comparable to response rates in anesthetizedrats. Individual cells showed excellent discrimination of odors,including mixtures overlapping by as much as 90%. Finally, odoraversion appeared to enhance selectivity of anterior piriformcortex neuron ensembles, potentially enhancing thediscriminability of learned aversive odors.#P149 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyStrategy for recombinant expression of functionalN-terminal domain of human T1R3 taste receptorproduced in Escherichia coliElodie Maîtrepierre, Maud Sigoillot, Loïc BriandUMR 1129 INRA-ENESAD-UB FLAVIC Dijon, FranceThe sweet taste receptor is a heterodimer composed of twosubunits called T1R2 and T1R3. Each subunit belongs to the classC of G protein-coupled receptors (GPCRs) and is constituted bya large extracellular N-terminal domain (NTD) linked to thetransmembrane domain by a cystein-rich region. T1R2 and T1R3NTDs are both able to bind natural sugars and some sweeteners(sucralose) with distinct affinities and undergo ligand-dependentconformational change. However, the relative contribution of thetwo subunits to the heterodimeric receptor function remainslargely unknown. To study the binding specificity of each subunitusing biochemical and structural approaches, a large amount ofpurified NTDs is suitable. Here, we report the production offunctional human T1R3 NTD from insoluble aggregated protein(inclusion bodies) expressed in high level in Escherichia coli.Transferring this protein into its native state by in vitro refoldingrequires screening to find buffer conditions and suitable additives.We established a factorial screen to detect folded functional T1R3NTD based on intrinsic tryptophan fluorescence quenching bysucralose. From the screen, we successively identified positivesynergistic interactions between additives on refolding of T1R3NTD. The soluble protein was then purified and characterized.Fluorescence and circular dichroism spectroscopy demonstratedthat T1R3 NTD is properly refolded and able to bind saccharidecompounds with physiological relevant affinities. To furthervalidate our expression strategy, we introduced single amino acidchanges in the predicted binding site using site-directedmutagenesis. The described production procedure in highquantity should be useful to perform structural and functionalstudies of human T1R3 and other T1R ligand-binding domains.P O S T E R SAbstracts | 73

#P150 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyIdentifying TRPA1 agonists by monitoring intracellularcalcium levels in HEK cellsPaige M. Roe, Erik C. Johnson, Wayne L. SilverWake Forest University Winston-Salem, NC, USANasal trigeminal chemoreceptors appear to be stimulated byvirtually all volatile compounds if presented in highconcentrations. Trigeminal nerve endings contain several differenttypes of receptors; however, the specific receptors stimulated bymany trigeminal stimuli are unknown. Transient receptor proteins(TRPs) are non-specific cation channels, associated withtrigeminal nerve fibers, which display an affinity for calcium.TRPA1, found in a subset of neurons in the trigeminal ganglion,has at least 90 different known agonists and was considered alikely target of known trigeminal stimuli that work through anunidentified mechanism. The goal of this experiment was todetermine if certain known trigeminal stimuli activate TRPA1.Both naive HEK and hTRPA1-HEK cells were allowed to growin a 96-well plate for a minimum of 24 hours. Intracellular calciumlevels were measured by a plate reader using the Ca 2+ -sensitivefluorescent dye FLUO-3AM. Baseline fluorescence of each wellwas measured. A potential TRPA1 agonist was then added andfluorescence was measured again. The relative change influorescence elicited by the test stimuli from wells containinghTRPA1-HEK cells was compared to the relative fluorescentchange elicited from wells containing naive HEK cells. In all,11 stimuli were tested in various concentrations ranging from0.1 mM to 100 mM. Based on preliminary data analysis, allylisothiocyanate, alpha-terpineol, acetic acid, benzaldehyde,cinnamaldehyde, eugenol, and d-limonene stimulated TRPA1.It is presently unclear whether amyl acetate, cyclohexanone,nicotine or toluene did or did not stimulate TRPA1. This methodidentifies TRPA1 agonists and future studies examiningbehavioral responses will assess whether trigeminal irritationdue to these stimuli is solely mediated by TRPA1.#P151 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyIn Vitro Nematocidal Activity of TRPA1 ActiveCompounds from Perilla FrutescensAngela Bassoli 1 , Gigliola Borgonovo 1 , Sara Caimi 1 , GabriellaMorini 2 , Francesco D’ErricoSeveral food plants used in traditional cooking contain interestingbioactive compounds. We are particularly interested inchemestetic compounds, both for their use in gastronomy and fortheir medical and agronomical applications. Perilla frutescensBritton (Labiatae) is a native plant of eastern Asia, where it ispopular as culinary and medicinal herb named keaennip in Koreaand shiso in Japan. One of the major components of Perillaessential oil is perillaketone PK. We discovered that this moleculeis a potent activator of TRPA1 in in vitro assays on rat clonedreceptors [2]. TRP ion channels are important cellular sensorsactivated by several stimuli and involved in many aspects ofchemical sensing [3,4]. In particular TRPA1 is involved innociception and has an established role in sensing mechanisms ininsects and invertebrates. This finding suggests that PK could beresponsible of specific nematocidal activity of Perilla extracts.We isolated pure PK from the leaves and evaluated its nematocidalactivity against second-stage larvae of cystic nematode Heteroderadaverti, showing that it is characterized by a remarkablenematocidal activity. [1] Handbook of herbs and spices vol. 3,Peter K.V. Ed., CRC Press, Boca Raton Boston New YorkWashington, DC 2006; [2] Bassoli A.; Borgonovo G.; Caimi S.;Scaglioni L.; Morini G.; Schiano Moriello A.; Di Marzo V.; DePetrocellis L., J. Bioorganic & Med. Chem., 2009, (DOI10.1016/j.bmc.2008.12.057); [3] Clapham D.E., Nature, 2003, 426,517-524; [4] TRP ion channels in sensory trasduction and cellularsignaling cascades, Liedtke, W.B.; Heller, S. Eds., Taylor andFrancis, 2007.#P152 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyOlfactory rivalry: Competing olfactory processing betweenthe two nostrils and in the cortexWen Zhou, Denise ChenRice University Houston, TX, USAWhen two different images are presented to the two eyes, weperceive alternations between seeing one image and seeing theother. Termed binocular rivalry, this visual phenomenon wasrecognized over a century ago, and its neural mechanism has beenconsiderably studied. Here we report the discovery of alternatingolfactory percepts when two different odorants are presented tothe two nostrils. We show that both cortical and peripheral(olfactory receptor) adaptations are involved in this process. Ourdiscovery extends the perceptual rivalry to olfaction, and opensup entirely new avenues to explore the workings of the olfactorysystem and olfactory awareness.#P153 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyIs there a difference in odor processing in response toleft vs. right-sided odor stimulation?Anna M. Kleemann 1 , Jessica Albrecht 1, 2 , Veronika Schöpf 3 ,Rainer Kopietz 1 , Katrin Haegler 1 , Rebekka Zernecke 1 ,Marco Paolini 1 , Imke Eichhorn 1 , Jennifer Linn 1 , HartmutBrückmann 1 , Martin Wiesmann 1,41Department of Neuroradiology, Ludwig-Maximilians-Universityof Munich Munich, Germany, 2 Monell Chemical Senses CenterPhiladelphia, PA, USA, 3 MR Centre of Excellence, MedicalUniversity Vienna Vienna, Austria, 4 Department of Radiology andNeuroradiology, Helios Kliniken Schwerin Schwerin, GermanyObjectives: The results of a previous localization studydemonstrated, that humans need trigeminal perception to localizeodors. Based on these findings a functional magnetic resonanceimaging (fMRI) experiment was carried out to assess whetherthere are differences in odor processing in response to left versusright-sided odorant stimulation. Methods: We used two odors:8ppm H 2 S (hydrogen sulphide), which is known to be a pureodorant in this concentration, and 17.5% isoamyl acetate (IAA)as an olfactory-trigeminal stimulus. We tested 22 healthy subjectswith H 2 S and 24 subjects with IAA. Functional images wereacquired using a 3T MR scanner. The odorant stimulation wasperformed using an olfactometer. The experiment was carried outbased on an event-related design paradigm and the stimulus lengthwas 500 ms. After every stimulus the participants were asked to74 | AChemS Abstracts 2009

discriminate between the H 2 S/IAA stimuli perceived either fromthe left or from the right nostril. Results and Conclusion: Wefound activations of brain areas specific for olfactory stimulation(piriform cortex, orbitofrontal cortex, insula) for both odors.Using ROI analysis we found differences in the primary olfactorycortex comparing left vs. right odorant stimulation in case of IAAodor, but not for H 2 S odor. These results supported our previousfindings and confirmed the hypothesis that nostril-specificdifferences in brain activation are functionally linked to successfulodor localization.#P154 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyBrain representation of subjective pleasantnessYaara Yeshurun, Yadin Dudai, Noam SobelWeizmann Institute of Science Rehovot, IsraelCaproate. Tones at three amplitudes served as an auditory control.The odorants varied in intensity as intended (F= 228, P L) revealed left Globus Pallidus, Piriform and Cingulateand right Insula. A hypothesis-driven analysis used the localizerto functionally restrict frontal (PirF) and temporal (PirT) piriformcortex, and then analyzed the event-related response within theseregions. There was an effect of intensity in left PirF, left PirT andright PirT (AUC for left PirF L-0.05%, M0.35%, H0.69%(F(2,20) = 6.84 p

#P157 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyThe effect of learning and attention on odor responses inpiriform cortexJennifer D Whitesell 1,2 , Wilder Doucette 1,2 , Diego Restrepo 1,21Neuroscience Program Denver, CO, USA, 2 Cell andDevelopmental Biology Denver, CO, USAThe piriform cortex (PC) is the primary target of afferent signalsfrom the olfactory bulb and is believed to be the site of odorperception. The anterior PC (aPC) receives more direct sensoryinput relative to the posterior PC, which has more intrinsicconnections. Recently it has become clear that the aPC is moreassociational in nature than was previously believed, with cellularodor responses that can change based on learning (Schoenbaum etal, 2007). We have found that cells in aPC display robust odorresponses, but only after an odor-reward association has beenlearned. We performed extracellular recordings from the aPC ofawake-behaving mice receiving a water reward paired with anodor stimulus. Animals initially received odor-water pairs onevery trial (all S+) and subsequently learned to discriminate oneunrewarded odor (S-) from a series of rewarded ones (multipleS+). Preliminary results indicate that aPC cells respond to odoronly when the animal has learned to identify an unrewarded odorin a series of rewarded ones. Passive sampling of odors or odordelivery paired with water reward did not elicit odor responses.Therefore, firing of cells in aPC may be modulated by attention,with cells only responding when the animal is attending to theodor stimulus. Comparing cellular responses when the animalmade a correct decision to responses during mistakes indicatesthat some cells respond primarily to odor, but the response ofmost cells depends on both odor and reward. Individual cells werevariable in the degree to which their response was modulated byreward or expectation of reward. In conclusion, cells in PC showcontext-dependent activity that is modulated by learning andattention.#P158 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyMapping Local Inhibitory Circuits in the Rat PiriformCortex using Photostimulation of Caged GlutamateVictor M. Luna, Diana L. PettitDept of Neuroscience, Albert Einstein College of Medicine Bronx,NY, USAThe piriform cortex (PC) is considered the major cortical centerfor integrating olfactory inputs from the olfactory bulb (OB). Keyto understanding PC computation is elucidating how principalexcitatory neurons are functionally connected to local inhibitorycircuits. To do this, we performed whole-cell recordings onsemilunar (SL) and pyramidal (Pyr) cells. We then focallystimulated interneurons (IN) in each of the anatomic layers of thePC (Ia, Ib, IIa, IIb, and III) using flash photolysis of cagedglutamate. Strength of inhibitory connections was assessed bymeasuring the peak amplitude, duration, and number ofinhibitory postsynaptic currents (IPSC) recorded from eachuncaging site. Our preliminary data indicate that PC-INconnections were stronger than SL-IN (mean IPSC numberacross all layers for Pyr vs SL, 3±0.5 vs 1±0.1; amplitude, 34.2±6.6vs 19.5±1.5 pA; duration, 79.8±12.3 vs 62.9±10.3 ms; n=6). Also,for either SL or Pyr, strength of connectivity depended on thelayer in which the uncaging beam was directed. SL and Pyrshowed the most robust IPSCs in response to uncaging at layerIIa, the weakest when uncaging at layer Ia. SL and Pyr showedmoderate responses to layer IIb uncaging. On the other hand, weobserved contrasting results between SL and Pyr when weuncaged at layer Ib and III. SL were strongly connected to layerIb cells, but weakly connected to layer 3 cells; the reverse was truefor Pyr. Thus, our results suggest that SL and Pyr may bedifferentially connected to distinct IN subsets. As such, SL andPyr would have unique input-output characteristics in response tothe same OB input. Understanding these marked computationalcapabilities may be important in deciphering the processesinvolved in encoding and representing olfactory information.#P159 Poster session III: Cortical chemosensory processing/Receptor genomics and molecular biologyThe olfactory bulb as cortical model systemThomas A. ClelandDept. Psychology, Cornell University Ithaca, NY, USAModel systems that reduce the scope and complexity of full-scalebiological systems while retaining the principal variables ofinterest have a distinguished history in neuroscience. Some of themost productive reduced model systems are those that enablemeaningful links between the cellular, circuit, and behaviorallevels of analysis, enabling study of their interplay. Olfactorylearning is a distributed phenomenon involving changes insynaptic weights and gene expression profiles throughout thecentral nervous system, thereby underlying a number of potentialchanges in animal behavior. My colleagues and I have sought toidentify an aspect of this broader odor learning that can belocalized within the olfactory bulb (OB). I here present the casefor olfactory generalization gradients, in both their nonassociative(cross-habituation) and associative (rewarded) forms, as plasticbehavioral measures dependent on learning and attention andmediated substantially by OB neural circuitry. Olfactorygeneralization gradients are regulated by multiple determinants oflearning including the amount of training, CS salience, US rewardvalue, and training-testing latency, as well as by neuromodulatoractivity within the OB. Aging and dementia model mice alsoexhibit shallower gradients after conditioning, indicative ofreduced learning rates. Computational circuit models are used toillustrate how known neuromodulatory effects can mediatecoordinated changes in OB odor responses and predict behavioraloutcomes. I suggest that these effects are microcosms of largerscalephenomena affecting cortical networks generally, and thatinsights gained from the reduced system of the OB therefore canbe applied to broader questions of cortical function anddysfunction.76 | AChemS Abstracts 2009

#P160 Poster session IV: Chemosensory transductionand perireceptor eventsPI3K-gamma in olfactory signal transduction in miceDaniela Brunert 1 , Kirill Y. Ukhanov 1 , Elizabeth A. Corey 1 ,Barry W. Ache 1,21Whitney Laboratory, Center for Smell and Taste, McKnight BrainInstitute, University of Florida Gainesville, FL, USA, 2 Depts. ofZoology and Neuroscience, University of Florida, Gainesville, FL,USAresponses to glutamate were measured in the presence and absenceof CNQX, an ionotropic AMPA/kainate glutamate receptorantagonist. CNQX partially blocked the responses to MSG inType III cells, suggesting that AMPA/kainate receptors arefunctionally expressed in these taste cells. Hence, both Type IIand Type III cells respond to MSG, but with different sensitivity.Further, responses to low concentrations appear to be at leastpartially mediated by AMPA/kainate receptors. This work wassupported by NIH grant DC00766 and a 3ARP grant fromAjinomoto.P O S T E R SRecent findings in rat olfactory receptor neurons (ORNs) suggestphosphoinositide 3-kinase (PI3K) -dependent signalling may playa role in mammalian olfactory signal transduction. In order tobring the power of genetically modified rodents to this questionwe tested whether PI3K has a similar effect on the output ofmouse ORNs. We show that the pan specific PI3K inhibitorWortmannin increases the calcium response of acutely dissociatedmouse ORNs to a complex odorant mixture (Henkel 100) inapproximately the same percentage of cells as with rat ORNs.The catalytic subunits of the alpha, beta and gamma isoforms ofPI3K are expressed in the mouse olfactory epithelium (OE) andcan be localized to the ORNs. As with rat ORNs, isoformspecificblockade of the beta (TGX-221) and gamma (AS252424)isoforms of PI3K implicate both isoforms in modulating odorantdependentsignalling. These results suggest that the PI3Kdependent modulation of olfactory signal transduction originallycharacterized in rats generalizes to mice. Mice deficient inPI3K-beta are embryonically lethal, but mice deficient inPI3K-gamma are viable and do not show obvious differences inOE morphology and retain cyclic nucleotide-dependentresponsiveness to odorants. These mice are being used to examinethe specific role and mechanism of PI3K-gamma in olfactorysignal transduction.#P161 Poster session IV: Chemosensory transductionand perireceptor eventsDifferential sensitivity to monosodium glutamate inType II and Type III taste cellsAurelie Vandenbeuch 1,2 , Catherine B. Anderson 1,2 ,Sue C. Kinnamon 1,21University of Colorado Denver and Health Sciences CenterDenver, CO, USA, 2 Rocky Mountain Taste and Smell CenterDenver, CO, USAGlutamate receptors are expressed in taste cells and allow thedetection of umami taste stimuli via the G protein coupledreceptor T1R1-T1R3. Glutamate receptors may also be involvedin neurotransmission between nerve fibers and taste cells, orbetween different taste cell types. The aim of the present studywas to compare the physiological response to monosodiumglutamate (MSG) in identified types of taste cells. We isolatedtaste cells from circumvallate papillae and used calcium imaging tocharacterize MSG responses. We used T1R3-GFP mice to identifya subset of Type II taste cells, presumably those that express theumami taste receptor T1R1-T1R3. We used stimulation with highK + to identify Type III cells, as these are the only cells in the tastebud that possess voltage-gated Ca 2+ channels. T1R3-GFP tastecells failed to respond to MSG at concentrations below 10 mM.On the contrary, in Type III cells, responses to MSG wereobtained at 100µM. To determine whether these responses to lowconcentration of glutamate are mediated by ionotropic receptors,#P162 Poster session IV: Chemosensory transductionand perireceptor eventsThe Second Messenger Pathways in TRPC2 KnockoutMouse Vomeronasal Sensory NeuronsChun Yang 1 , Peng Zhang 2 , Rona J Delay 11Department of Biology, Vermont Chemical Sensory group,University of Vermont Burlington, VT, USA, 2 MassachusettsGeneral Hospital and Harvard Medical School Charlestown,MA, USAIn vomeronasal sensory neurons (VSNs), transient receptorpotential cation channels (TRPC2) play a large role in responsesto pheromones and odorants. TRPC2-/- mice fail to display themale-male aggressive behavior and mate indiscriminately (Stowerset al., 2002). However, pregnancy block, which requires afunctional vomeronasal organ (VNO), does occur in TRPC2-/-mice (Kelliher et al., 2006). This suggests the presence of aTRPC2-independent pathway in VSNs. To reveal the mechanismfor pheromone/odorant detection of VSNs, we investigated urineresponse in VSNs from wild-type and TRPC2-/- mice. Usingperforated patch clamp technique, we recorded responses to diluteurine in wild-type & TRPC2-/- VSNs. These urine responses inboth types appeared to be through the phospholipase C (PLC)pathway since they were completely blocked by the PLCinhibitor, U73122, although the response amplitude of TRPC2-/-VSNs was smaller than that for wild type. We asked which secondmessenger pathway mediates urine responses in knockout mice.Activation of the PLC pathway produces diacylglycerol (DAG),which directly gated TRPC2 chanels. However, DAG alsoproduces arachidonic acid (AA) via DAG lipase. Thus, we testedif a DAG lipase inhibitor, RHC80267, altered urine responses.We found that RHC80267 blocked urine-induced inward currentby ~60% in wild type VSNs while it abolished the urineresponses in TRPC2-/-. Moreover, AA itself induced an inwardcurrent in both wild type and knockout VSNs that was dependenton extracellular calcium. Using inside-out patches, we recordedCa2+-activated and AA-activated channel activity with aconductance of ~26 pS. Thus, our data suggested that in mouseVSNs, the pheromone/odor detection is carried out by bothDAG-TRPC2 and Ca2+/AA-cation channels pathways.Abstracts | 77

#P163 Poster session IV: Chemosensory transductionand perireceptor eventsPI3K mediated signaling in lobster olfactory signaltransductionElizabeth A Corey 1 , Adeline Pezier 1 , Katharina Klasen 1 ,Barry W Ache 1,21Whitney Lab University of Florida St Augustine, FL, USA,2Center for Smell and Taste, and McKnight Brain Institute Depts.of Zoology and Neuroscience, University of Florida Gainesville,FL, USAOdors are identified by the brain through a distributed processthat begins with the primary olfactory receptor neurons(ORNs). In organisms in which odorant molecules bind toG protein-coupled receptors (GPCRs) on the ORNs to initiatesignal transduction, involvement of phosphoinositide 3-kinase(PI3K) activity in olfactory signal transduction would suggesta potential role for the GPCR-activated class I PI3K b and gisoforms. Using isoform-specific antibodies, we identified aprotein in the olfactory signal transduction compartment oflobster ORNs that is immunoreactive with an antibodydirected against mammalian PI3Kg. The lobster PI3K coimmunoprecipitateswith the a and bg G protein subunits, andan odorant-evoked increase in phosphatidylinositol (3,4,5)-trisphosphate, the product of PI3K activity, can be detected inmembranes prepared from the signal transduction compartmentof the ORNs. The isoform-specific PI3Kg inhibitorAS-252424 reduces the odor-evoked output of lobster ORNsin vivo. Additionally, the catalytic subunits of PI3Kb and g, aswell as odorant-dependent PI3K activity, can be detected in aciliary membrane preparation from rat ORNs. Collectively,these findings support a potential role for PI3K-dependentphospholipid signaling in olfactory transduction and suggestthat PI3K-mediated signaling in olfactory signal transductionmay be conserved across species.#P164 Poster session IV: Chemosensory transductionand perireceptor eventsDifferent response properties between Type II andType III taste bud cells in mouse fungiform papillaeRyusuke Yoshida 1 , Toshiaki Yasuo 1 , Yoshihiro Murata 1 , MasashiJyotaki 1 , Yuchio Yanagawa 2 , Kunihiko Obata 3 , Hiroshi Ueno 4 ,Robert F. Margolskee 5 , Yuzo Ninomiya 11Sect. of Oral Neurosci., Grad. Sch. of Dental Sci., Kyushu Univ.Fukuoka, Japan, 2 Grad Sch. of Med., Gumma Univ. Maebashi,Japan, 3 RIKEN Wako, Japan, 4 Nara Women’s Univ. Nara, Japan,5Mount Sinai Sch. of Med. NY, NY, USATaste bud cells are classified into 4 groups (Type I ~ IV) accordingto their morphological and functional characteristics. Amongthem, Type II cells express sweet, bitter and umami taste receptorsand transduction components, suggesting that Type II cells maybe responsible for these taste qualities. Type III cells possessputative sour taste receptors, suggesting that these cells may besour taste receptor cells. To clarify taste response properties ofType II and III cells, we investigated taste responses of individualmouse fungiform taste bud cells expressing gustducin (Type II) orGAD67 (Type III). We recorded taste responses from gustducin-GFP and GAD67-GFP taste bud cells, or examined theexpression of gustducin and GAD67 by the single cell RT-PCRafter recording of taste responses. Both Type II and III cellsgenerated action potentials in response to taste stimuli, suggestingthat these cells may transmit taste information to gustatory nervefibers. Type II cells responded best to sweet, bitter, or umamistimuli whereas Type III cells responded to sour stimuli andelectrolytes. These results are well consistent with those ofprevious molecular studies and suggest that Type II and Type IIIcells may contribute to detection and perception of different tastequalities. Supported by KAKENHI 18077004, 18109013 (YN)and 19791367 (RY).#P165 Poster session IV: Chemosensory transductionand perireceptor eventsReceptor-dependent PIP 2 resynthesis restores sweet andbitter inhibitions of potassium currentsFang-li Zhao, Scott HernessThe Ohio State University Columbus, OH, USAPhosphatidylinositol 4,5-bisphosphate (PIP 2 ), a lipid signalingagent, is a recognized component of sweet, bitter, and umamitransduction cascades. It is also a well known activator of ionchannels in other cellular systems. We previously established PIP 2resynthesis as important in restoring activity to outward (K V ) andinward (K IR ) potassium currents in rat posterior taste receptorcells (TRCs) after caffeine-inhibition. Here we providecorroborative evidence that suggests PIP 2 resynthesis generalizesin adaption to bitter and sweet stimuli. Kv currents, recordedfrom rat posterior TRCs with standard patch clamp techniques,were inhibited approximately 35% by m-3M3FBS, a broadspectrum PLC activator that acts to globally deplete PIP 2whether applied intracellularly (100 µM, n=32) or extracellularly(5 µM, n=57). o-3M3FMS (100 M, intracellular), an inactiveenantiomer, was without effect. Unexpectedly, depletion of PIP 2strongly influenced response profiles to cycloheximide (100 M;n=61), caffeine (20 mM; n=44), and SC45647 (100 M;n=56). After m-3M3FBS treatment, these tastants, known toinhibit K V , now actually enhanced K V . We hypothesize that thiseffect is due to PIP 2 resynthesis. To test this notion, polylysine, aPIP 2 scavenger, was added to the pipette solution and effectivelyreduced the enhancement caused by bitter (n=22) or sweet (n=19)stimulation. In addition, exogenous PIP 2 itself (10 M, n=33, 50M, n=27) did not enhance K V although 50 M PIP 2 was able toreduce K V inhibition when combined with 5 M m-3M3FBS(n=20). Collectively, these data support the notion that potassiumchannels are subject to dynamic regulation by PIP 2 and that itsresynthesis requires a signal, likely receptor-mediated, for itsinitiation.#P166 Poster session IV: Chemosensory transductionand perireceptor eventsNative TRPM5 currents recorded from posterior rat tastereceptor cellsFangli Zhao, Luc Jaber, Randy Hivley, Scott HernessThe Ohio State University Columbus, OH, USAThe ion channel TRPM5 is expressed in a subset of taste receptorcells (TRCs) and is thought essential for bitter, sweet, and umamitransduction cascades. It is permeable to monovalent cations andgated by intracellular calcium. This channel has mostly beencharacterized in heterologously expressed cells, where it is not78 | AChemS Abstracts 2009

subject to native regulatory mechanisms. Here we presentrecordings of TRPM5 currents from native rat posterior TRCsusing standard patch clamp techniques with cesium electrodes toblock potassium current. Using flash photolysis (with caged-IP 3or caged Ca 2+ ) or ionomycin (a calcium ionophore), a TRPM5-like current was consistently evoked in half of tested TRCs. Thecurrent displayed strong desensitization, rectification, dependenceon extracellular sodium, and was unaffected by a TRPM4 channelblocker. Additionally, the tastants cycloheximide or SC45647(each at 100 M) were demonstrated to evoke highly similarcurrent in a subpopulation of TRCs. As expected, the IP 3 -receptor blockers, 2-APB and heparin, and thapsigargin, aninhibitor of intracellular calcium stores, diminished the activationand amplitude of the TRPM5 current. Quinine, reported toinhibit TRPM5 currents, similarly had an inhibitory action on thiscurrent. Further the current was modulated by application of thelipid signaling agent PIP 2 which also promoted bitter and sweettastant-elicited TRPM5 responses. The current could also beevoked by arachidonic acid (AA) further suggesting itsmodulation by lipid regulators. Preliminary data from HEK293cells expressing mouse trpm5 supports our results from nativeTRCs with evoked currents displaying similar activation anddesensitization kinetics. Collectively, these data support thenotion that we are recording native TRPM5 currents from asubset of TRCs.#P167 Poster session IV: Chemosensory transductionand perireceptor eventsNovel Insights into Odorant Recognition: A Computationaland Functional Analysis of Ligand Binding to the HumanOlfactory Receptor OR2AG1Lian Gelis 1 , Steffen Wolf 2 , Klaus Gerwert 2 , Hanns Hatt 1 ,Eva M. Neuhaus 11Department of Cellular Physiology, Ruhr-University BochumBochum, Germany, 2 Department of Biophysics, Ruhr-UniversityBochum Bochum, Germany#P168 Poster session IV: Chemosensory transductionand perireceptor eventsOlfactory Neuron Response Statistics: a Cross Species AnalysisRafi Haddad 1,2 , David Harel 1 , Noam Sobel 21Department of Computer Science and Applied MathematicsRehovot, Israel, 2 Department of Neurobiology, the WeizmannInstitute of Science Rehovot, IsraelAlthough the olfactory systems of different species shareremarkable organizational similarities, there are also markeddifferences between them, most notably the number of receptortypes and their response dynamics. The reasons for, andimplications of these differences, are largely unknown. Here weanalyzed a large set of previously published olfactory neuralresponse data from different olfactory neurons in six differentspecies. We found that whereas species with a small number ofolfactory receptor (OR) types have more broadly tuned responsecurves, species with larger number of OR types tend to have morenarrowly tuned response curves. Consistent with this, specieswith larger number of OR types were better at discrimination ofenantiomers. Comparing the response spectra of all olfactoryneurons from the different species, we found that only a small setof olfactory neurons had similar response spectra. This lack offunctional conservation is consistent with genetic analysis, thattogether suggest each species may have olfactory receptors thatare optimized for its own ecological niche. Despite thesedifferences, we found that in all species tested, and across 12unrelated reported studies, the primary axis of the olfactoryneuronal space was the “total neuronal response” elicited bythe odors. In other words, summing the neural response elicitedby an ensemble of olfactory neurons to a specific odor accountsfor a large portion of the neural response variability. Critically,this primary axis of neural space was significantly correlated tothe odor preferences of rats, mice and drosophila. We thereforesuggest that the primary axis of neural response is related toodor hedonics.P O S T E R SThe process of odor perception begins with the binding ofodorant molecules by specific odorant receptors (ORs). So far,only few ligand-OR interaction pairs have been characterized andmost characterized receptors show a rather broad tuning anddetect multiple, chemically similar odorants. Due to the limitedknowledge on receptor – odorant interaction, the moleculardetails of ligand specificities of ORs are not well understood.Highly variable residues in the transmembrane domains III, IV,and V were postulated to form the basis for ligand specificity. Togain more insight into the molecular basis of odor recognition, weinvestigated ligand-receptor interactions for the human olfactoryreceptor OR2AG1 by combining dynamic homology modelingand ligand docking with functional analysis and site-directedmutagenesis. Basing on the rhodopsin crystal structure, wepredicted the protein structure of OR2AG1 by homologymodeling. The model was further subjected to free moleculardynamics simulations in an explicit membrane/solventenvironment with various odorants introduced into the putativebinding site. To verify the theoretical model experimentally wemutated amino acids predicted to be involved in ligand bindingand compared activation of receptor variants heterologouslyexpressed in Hana3a cells by Ca 2+ -imaging. By combiningtheoretical and experimental techniques it was possible tocharacterize ligand binding of OR2AG1 on the atomic scale.#P169 Poster session IV: Chemosensory transductionand perireceptor eventsDeterminants of Agonist Sensitivity in an Insect OlfactoryReceptorAndrew S. Nichols, Charles W. LuetjeMolecular and Cellular Pharmacology, University of Miami,Miller School of Medicine Miami, FL, USATo identify functionally important structural features ofDrosophila olfactory receptors (DmOrs), we expressed DmOrsOr35a, Or85a, and Or85b in Xenopus oocytes (each with Or83b),and screened for susceptibility to methanethiosulfonate (MTS)reagents. These reagents may alter receptor function by covalentlyattaching to accessible cysteines, thus providing an approach forstructural studies. One receptor, Or85b, was partially inhibited byMTSES (ES). We mutated each of the five cysteine residues (C124,C146, C208, C278, and C311) to serine and showed that onlymutant C146S failed to be inhibited by ES, suggesting C146 as thesite of ES covalent attachment and receptor inhibition.Comparison of current-voltage relationships before and after EStreatment indicated no effect on the ionic permeability propertiesof the receptor, suggesting that ES is not acting at the channelpore. Increasing agonist concentration reduced the inhibitoryability of ES, suggesting that ES was shifting the dose-responseAbstracts | 79

elationship of the receptor and its agonist, 2-heptanone. Indeed,ES treatment increased the EC 50 for 2-heptanone by 4-fold,indicating that residue 146 is at, or near, a region involved inagonist sensitivity. Next, we probed this region using thesubstituted cysteine accessibility method. Residues 134 to 154were sequentially mutated to cysteine in an Or85b C146Sbackground (the mutant insensitive to ES) and screened forsusceptibility to ES, enabling identification of other residuesimportant for agonist sensitivity. The M148C mutation restoredsusceptibility to ES in the C146S receptor. We conclude that theextracellular end of transmembrane domain 3 (the location ofC146 and M148 in DmOr85b) is involved in determining agonistsensitivity of this insect olfactory receptor.#P170 Poster session IV: Chemosensory transductionand perireceptor eventsVisualization of Assayed Olfactory Chemical SpaceZita Peterlin, Armen Enikolopov, Stuart FiresteinColumbia University New York, NY, USAThe diversity of chemical ligands potentially detectable byolfactory receptors makes investigating how these proteins extractand encode information a particularly fertile area of study. Yet thesame richness that makes this system so attractive often posespractical challenges for experimental design. In an effort to assistin selection of subregions of olfactory space, we present a visualmap of the compounds that currently have been assayed onidentified human and rodent olfactory receptors. This guidedepicts the relationship between major “nodes of empirical focus”and provides a means of readily comparing the receptive fieldsbetween olfactory receptors. An accessory view organizes assayedcompounds into a three-dimensional landscape based on physicalchemicaldescriptors to permit a more objective evaluation of therange of tested chemical space. We believe that this tool can helpstimulate further evaluation of the coding logic employed by thesereceptors that have already proven amenable to expression invarious systems.#P171 Poster session IV: Chemosensory transductionand perireceptor eventsPhosphoinositide-3-kinase Dependent Signaling inMammalian Olfactory Receptor NeuronsKirill Ukhanov 1,2 , Elizabeth A. Corey 1 , Katharina Klasen 1,2 ,Daniela Brunert 1,2 , Barry W. Ache 1,2,31University of Florida, Whitney Laboratory St.Augustine, FL,USA, 2 University of Florida, Center for Smell and Taste,McKnight Brain Institute Gainesville, FL, USA, 3 University ofFlorida, Depts. of Zoology and Neuroscience Gainesville, FL, USAPhosphoinositide-3-kinase (PI3K)-dependent signaling canmodulate the calcium response of rat olfactory receptor neurons(ORNs) to odorant stimulation (Spehr et al., Neuron, 2002).Here we report that Western blotting and immunohistochemistryconfirms the presence of two isoforms of PI3K known to beactivated by GPCRs in other systems (beta and gamma) in ratolfactory ciliary membranes and in most or all ORNs in freshfrozen sections of the rat olfactory epithelium (OE). The complexodorant Henkel100 transiently increases the level of PIP 3 ,generally assumed to be the primary product of PI3K in vivo, inrat olfactory ciliary membranes as fast as 2 sec followingstimulation. Production of PIP 3 is significantly reduced bythe pan-specific PI3K blocker, LY294002, as well as by the PI3Kbeta- and gamma-specific blockers, TGX221 and AS252424,respectively. The pan- and the gamma-specific PI3K blockerscan modulate Henkel100-induced discharge in rat ORNsmeasured in the intact OE through loose-patch recording fromdendritic knobs. PI3K-dependent modulation can account foralmost a 10-fold shift in the overall sensitivity of the ORNs.Activation of P 2 Y purinergic receptors, also thought to coupleto phosphoinositide signaling, fails to modulate odorant responsesin a PI3K-dependent manner. We conclude that odorantsactivate PI3K through a G-protein coupled pathway, and do sosufficiently fast to modulate the electrophysiological output ofrat ORNs in a transduction-dependent context.#P172 Poster session IV: Chemosensory transductionand perireceptor eventsThe Effects of Membrane Permeant and ImpermeantCarbonic Anhydrase Inhibitors on the EOG and NMPResponses to CO 2 in MiceLee Coates 1,2 , Tabitha L. Novosat 2 , Ryan J. Hanson 2 ,Shane P. Hennessy 2 , Jessica K. Kenemuth 21Department of Biology, Allegheny College Meadville, PA, USA,2Neuroscience Program, Allegheny College Meadville, PA, USAPhysiological concentrations of CO 2 (less than the 4-5% CO 2 inexpired air) have been shown to stimulate a subset of olfactoryreceptor neurons, while noxious CO 2 concentrations (25% orabove) are known to stimulate trigeminal nerve endings in thenasal epithelia. Although the mechanism by which CO 2stimulates olfactory receptors or trigeminal nerve endings is notknown it appears that the enzyme carbonic anhydrase (CA) playsa role in the transduction mechanisms. CA is located in the nasalmucosa as well as in a small percentage of olfactory receptorneurons. The objective of this study was to record electroolfactograms(EOG) and negative mucosal potentials (NMP) inresponse to CO 2 before and after topical application ofmembrane permeant (acetazolamide - AZ) or membraneimpermeant (quaternary ammonium sulfanilamide - QAS) CAinhibitors. A range of CO 2 concentrations, from 0 to 50%, wasused in this study. Topical application of mammalian Ringers didnot affect the EOG responses to CO 2 while 0.1mM QAS caused asmall decrease in EOG amplitudes and 0.1mM AZ eliminated theEOG responses to all CO 2 concentrations. Topical application ofmammalian Ringers, 0.1mM QAS, or 0.1mM AZ caused a smalldecrease in the NMP at each CO 2 concentration. These resultsindicate that intracellular CA plays a critical role in the detectionof CO 2 by olfactory receptor neurons. Although inhibition ofextracellular CA caused a small decrease in the EOG responses toCO 2 it is not clear whether this indicates a specific role formucosal CA or is due to non-specific effects on mucosal pH.The results from the NMP experiments indicate that extracellularand intracellular CA play no role or only a minor role in thedetection of CO 2 by trigeminal nerve endings.80 | AChemS Abstracts 2009

#P173 Poster session IV: Chemosensory transductionand perireceptor eventsIdentification of a novel Calcium Activated Chloride Channelin the Cilia of Olfactory Sensory Neurons: TMEM16bStefan Kurtenbach* 1 , Sebastian Rasche* 1 , Bastian Tötter 1 , JennyAdler 2 , Astrid Tschapek 2 , Hanns Hatt 1 , Bettina Warscheid 2 ,Eva M. Neuhaus 21Department of Cell Physiology, Ruhr-University, Bochum,2Medical Proteome-Center, Ruhr-University, Bochum,* both authors contributed equally to this workChloride channels are a ubiquitous group of ion channelsinvolved in many physiological processes, including sensorysignal transduction. The chloride channel involved in olfactorysignal transduction belongs to the family of chloride channelsthat are regulated by the cytosolic Ca 2+ concentration. These Ca 2+ -activated chloride channels (CaCCs) can conduct Cl- ions uponactivation by calcium, but only little is known to date about theirstructure and function.olfactory signal termination. Olfactory tissue displays high CYPand UDP-glucuronosyltransferase activities. Thebiotransformations catalyzed by these enzymes could thereforelead to the inactivation of odorants. In the present study, westudied the impact of odorant glucuronidation and oxidation onolfactory signal in rat using a submerged electro-olfactogram(EOG) technique. EOG amplitudes produced by twocompounds, 4-methyllumbelliferone and quinoline, werecompared to those generated by the glucuronide and oxidizedforms. The native forms elicited dose-dependent responses.No EOG responses were recorded when stimulating the samepreparation with the glucuronides. The hydroxylated metabolite,8-hydroxyquinoline, produced a response half-way between thoseobtained with the non-hydroxylated native form and theconjugated form. The signals of mixtures containing both thenative and the glucuronide forms were equivalent to thoseobserved with the native molecules, indicating that metabolites donot compete with unmetabolized molecules. These data areconsistent with the hypothesis that biotransformation of odorantmolecules, particularly glucuronidation, can lead to a decrease ofthe olfactory input.P O S T E R SWe performed a proteome analysis of the olfactory epitheliummembrane proteome and identified so far uncharacterizedmembrane proteins as candidate channels. One of the mostabundant membrane proteins was TMEM16b, a member of arecently identified family of CaCCs. We show here with in-situhybridization and RT-PCR that TMEM16b is expressed inmature olfactory sensory neurons. Western blot analysis with anantibody specifically designed to detect TMEM16b revealed thatits expression is different from the closely related TMEM16aprotein, which shows a broad expression pattern in secretoryepithelial cells. TMEM16b expression was found to be highlyspecific for the olfactory epithelium and the retina, the proteinwas not detected in other tissues such as lung, kidney, liver, testis,trachea, colon, and tounge. TMEM16b localization is restricted tothe cilia of the olfactory receptor neurons. The localization in theolfactory neurons is in agreement with electrophysiologicalrecordings showing expression of CaCCs in the ciliarymembranes. Since the channels were shown to be involved ingenerating the receptor current during odor detection, we arecurrently investigating odor responses upon TMEM16b siRNAtransfection of the olfactory epithelium with electro olfactogramrecordings (EOGs).#P174 Poster session IV: Chemosensory transductionand perireceptor eventsBiotransformation of odorants modifies the olfactory signalNicolas Thiebaud 1 , Stéphanie Véloso Da Silva 2 , Ingrid Jakob 2 ,Gilles Sicard 2 , Yves Artur 1 , Jean-Marie Heydel 1 , Anne-MarieLe Bon 11UMR 1129 FLACIC INRA Université de BourgogneENESAD DIJON, France, 2 UMR CESG 5170 CNRSUniversité de Bourgogne, INRA DIJON, FranceThe olfactory epithelium contains several families of enzymesinvolved in biotransformation of chemicals, such as cytochromeP450-dependent monooxygenases (CYP) and transferases. Someof them are specifically expressed in olfactory tissues. While theseenzymes are mostly responsible for the detoxification of inhaledtoxic compounds, at this peculiar location, they could also play arole in the biotransformation of odorants and contribute to the#P175 Poster session IV: Chemosensory transductionand perireceptor eventsHomeostatic Control of Sensory Output in BasalVomeronasal Neurons: Activity-Dependent Expression ofEther-à-Go-Go Related Gene Potassium ChannelsSilke Hagendorf, Corinna Engelhardt, Daniela Fluegge,Marc SpehrDepartment of Cellular Physiology, Ruhr-University Bochum,GermanyConspecific chemosensory communication controls a broad rangeof social and sexual behaviors. In most mammals, socialchemosignals are predominantly detected by sensory neurons of aspecialized olfactory subsystem - the vomeronasal organ (VNO).The behavioral relevance of social chemosignaling puts highdemands on the accuracy and dynamic range of the underlyingtransduction mechanisms. However, the physiological conceptsimplemented to ensure faithful transmission of social informationremain widely unknown. Here, we show that sensory neurons inthe basal layer of the mouse VNO dynamically control theirinput-output relationship by activity-dependent regulation ofK+ channel gene expression. Using large-scale expressionprofiling, immunochemistry and electrophysiology, we providemolecular and functional evidence for a role of ether-à-go-gorelated gene (ERG) K+ channels as key determinants of cellularexcitability. Our findings indicate that an increase in ERG channelexpression extends the dynamic range of the stimulus-responsefunction in basal vomeronasal sensory neurons. This novelmechanism of homeostatic plasticity in the periphery of theaccessory olfactory system is ideally suited to adjust VNOneurons to a target output range in a layer-specific and usedependentmanner.Abstracts | 81

#P176 Poster session IV: Chemosensory transductionand perireceptor eventsMovement of Pheromone Inside Insect Olfactory SensillaeThomas M DykstraDykstra Laboratories, Inc. Gainesville, FL, USAPheromones of the order Lepidoptera (butterflies and moths) arecommonly straight-chain fatty acids. Hence, they are quiteinsoluble in the aqueous layer of the sensillar lymph. The currenttheory of insect olfaction asserts that in order to become soluble apheromone must bind with a pheromone binding protein, orPBP. This pheromone/PBP complex then diffuses across thesensillar lymph to eventually bind with a putative proteinreceptor. A review of the literature was conducted to ascertain ifdiffusion is a sufficient mechanism in order to support the currenttheory. The review finds that the diffusion coefficient is too slow(0.12 square micrometers/millisecond) when considering a 250dalton pheromone and the bound PBP at 14,000 daltons. Alreadytoo slow to explain the electrophysiological evidence (1-10 ms)there are other reviewed factors to consider which will furtherslow the diffusion coefficient. These include a non-linearmathematical extrapolation, a concentration of 10 mM PBP in thesensillar lymph, no diffusion gradient within the lymph, boundwater molecules to the PBP, and changes in concentration orviscosity over time. Based on known physical laws, diffusioncannot be the sole mechanism involved in insect olfaction. If theelectrophysiological evidence supports pheromone detection infrom 1-10 ms, then either a different mechanism must beoccurring, or additional mechanisms must be proposed.A scientific reassessment of the possible mechanisms is warranted,but new theories must be able to explain the electrophysiologicalevidence, not contradict it.#P177 Poster session IV: Chemosensory transductionand perireceptor eventsPathophysiological role of ENaC in a mammalian model ofdiabetesArian F Baquero, Stephanie Croasdell, Timothy A GilbertsonUtah State University Logan, UT, USAUntreated diabetes is a profound disease that is reflected in asevere impairment of systemic salt and water balance. Based onour earlier work demonstrating the insulin regulation of epithelialsodium channels (ENaC), we hypothesize that ENaC in mousetaste receptor cells (TRCs) plays a central role in the restorationof salt and water intake by virtue insulin’s effect on the gustatorysystem. To investigate whether ENaC function is altered duringthe onset of diabetes, we performed functional ratiometric Na +imaging in isolated taste cells from a mouse model of Type 1(insulin-dependent) diabetes. Taste cells from diabetic miceexhibit Na + responses and amiloride sensitivity similar to non–diabetic littermates. However, insulin enhancement of Na + influxvia ENaC was abolished in diabetic taste cells. In contrast, tastecells from diabetic mice, especially those in the posterior mousetongue, evoke greater responses to 140 mM NaCl (60±5.3 AUC)than those from non-diabetic mice (26.4±5.4). To evaluate theeffects of the diabetic state in salt taste, we next characterizedbehavioral responses to NaCl using a brief access test. Diabeticmice showed avoidance of NaCl at significantly lowerconcentrations than the non-diabetic group. In contrast, diabeticanimals showed no significant avoidance to these NaCl solutions(p

G protein-coupled receptors for bitter, sweet and umamicompounds, and are the source of ATP secretion. These cells arebelieved to secrete ATP through gap junction hemichannels.Based on studies from isolated taste cells, we have postulated thatATP secreted from Receptor cells acts within the taste bud toexcite adjacent Presynaptic (Type III) cells (Huang et al2007). This however, remains to be established in more intactpreparations. Here we use lingual slices containing intact tastebuds to test the hypothesis in detail. We used confocal Ca 2+imaging to track taste stimulation of Receptor and Presynaptictaste cells. Incubating the tissue with an ecto-ATPase (apyrase,30 units/ml) reversibly blocked signal transfer from Receptorto Presynaptic cells, consistent with ATP being thetransmitter. Inhibiting pannexin 1 (Px1) gap junctionhemichannels with CO 2 -saturated buffer reduced cell-cellsignaling (N.B., intracellular acidification with CO 2 -buffer is apotent blocker of Px1 channels). Moreover, probenecid (1 mM),an antagonist of Px1 channels (Silverman et al 2008; Ma et al 2008)significantly reduced cell-cell signaling between Receptor andPresynaptic cells. These findings strongly support the hypothesisthat in situ, gustatory Receptor cells secrete ATP via Px1hemichannels when taste buds are stimulated and that thereleased ATP excites adjacent Presynaptic cells. These findingsare being used to develop a model for signal processing inmammalian taste buds.#P180 Poster session IV: Chemosensory transductionand perireceptor eventsTaste cells express and secrete glucagon-like peptide 1Zaza Kokrashvili, Robert F. MargolskeeMount Sinai School of Medicine New York, NY, USA#P181 Poster session IV: Chemosensory transductionand perireceptor eventsSodium/calcium exchangers selectively contribute to theregulation of cytosolic calcium levels in mouse taste cellsAgnieszka I. Laskowski, Kathryn F. MedlerUniversity at Buffalo Buffalo, NY, USAThe detection of gustatory stimuli depends on the activation ofdiverse signaling pathways that are selectively expressed in tastereceptor cells in the oral cavity. Some taste stimuli activateG-protein coupled receptors (GPCRs) that cause calcium releasefrom intracellular stores while other stimuli depolarize taste cellsto cause calcium influx through voltage-gated calcium channels(VGCCs). We have recently shown that activation of these twotypes of signaling pathways generate significantly differentcalcium responses within taste cells (Hacker et al., 2008) and wepredicted that the mechanisms needed to regulate these differentcalcium loads may also differ. To date, however, the calciumbuffering mechanisms in taste cells have not been well studied.We recently demonstrated that mitochondria make significantcontributions to the regulation of cytosolic calcium in taste cells(Hacker & Medler, 2008) but no other calcium bufferingmechanisms in taste cells have been identified. In this study, weused calcium imaging to characterize the role of sodium/calciumexchangers (NCXs) in regulating cytosolic calcium in tastecells. We found that NCXs make important contributions to themaintenance of resting calcium levels in taste cells and that theseproteins selectively contribute to the regulation of evoked calciumresponses. RT-PCR analysis revealed that multiple NCX andsodium/calcium/potassium exchangers (NCKX) are expressed intaste cells.P O S T E R SWe previously observed that gustducin, T1r receptors and severalother taste signaling elements are expressed in duodenalenteroendocrine L cells that express glucagon-like peptide 1(GLP-1). We determined that gustducin and T1r3 are critical toenteroendocrine L cell release of GLP-1 in response to glucose.A number of years ago we speculated that if the gut’s L cellsexpressed taste elements then taste cells might in turn expressGLP-1 and other L cell hormones. We have found that this isindeed the case and have examined the function of hormonesreleased from these “endocrine taste cells.” METHODS: RT-PCR, in situ hybridization and immunohistochemistry were usedto examine expression of GLP-1 and other gut hormones in tastecells. ELISA was used to monitor in vivo release of GLP-1 fromtaste cells into the bloodstream in response to glucose and othertastants. Esophagealectomy/vagotomy was done to eliminatedirect or indirect stimulation of enteroendocrine L cells in gut.Circumvallate papillae explants in culture were examined for theability to release GLP-1 after tastant stimulation. RESULTS:Taste cells were found to express GLP-1, glucagon, PYY andother gut hormones. Patterns of expression indicated thatgustducin-expressing type II cells and other subtypes of taste cellsexpress GLP-1. In wild-type mice, with or without vagotomy,application of glucose to the tongue induced a rapid elevation ofGLP-1 in the bloodstream. Stimulation of taste cell explants withglucose led to release of GLP-1 into the medium. Glucosestimulation of gustducin-null mice did not lead to significantrelease of GLP-1 from taste cells in vivo or in explants.CONCLUSIONS: The cephalic phase rise in circulatingGLP-1 depends on direct release of GLP-1 from gustducinexpressingtaste cells into the bloodstream.#P182 Poster session IV: Chemosensory transductionand perireceptor eventsThe multiple PDZ domain protein 1 (MUPP1) – Role in theolfactory signal transduction cascadeSabrina Baumgart, Ruth C. Dooley, Hanns Hatt, Eva M.NeuhausRuhr-University Bochum Bochum, GermanyThe complex network of the olfactory signal transductionpathway, found in olfactory sensory neurons (OSNs), enablesmammals to detect and discriminate between thousands ofdifferent odorants. Until now, the importance of organizing thevarious interaction partners of olfactory receptors (ORs) is notwell understood. For diverse cell signalling cascades interactionswith PDZ domain containing proteins, which assemble definedprotein networks and thereby regulate signalling events, arecharacterized. The Multiple PDZ Domain Protein 1, MUPP1,consists of 13 individual PDZ domains and interacts withdifferent GPCRs such as the serotonin receptor 5-HT 2c and theGABA B receptor. We demonstrate that this scaffolding protein ishighly expressed in the dendritic knobs and cilia of olfactorysensory neurons. We further found that ORs and MUPP1 interactin vitro and in the recombinant expression system. ThereforeMUPP1 represents a possible nucleator or regulator of theolfactory response by acting as first building block of a putative“olfactosome”. The physiological role of MUPP1 inchemosensory systems and the identification of unknowninteraction partners are currently investigated.Abstracts | 83

#P183 Poster session IV: Chemosensory transductionand perireceptor eventsGurmarin inhibits the Sweet Receptor by Binding to theVenus Fly Trap Module of T1R3Emeline L. Maillet, Laura Pelletier, Timothy J. Cardozo,Jeniffer Quijada, Prisca Silie, Baohua Zhao, Yuzo Ninomiya,Marianna Max, Robert F. MargolskeeMount Sinai School of Medicine, Department of Neuroscience.Box1065 New York, NY, USAGurmarin is a polypeptide of 35 amino-acids that suppressesbehavioral and gustatory neural responses of rodents to sweetcompounds without affecting responses to salty, sour, or bittersubstances. Gurmarin has no detectable effect in humanpsychophysical studies. Here, we show that gurmarin acts onmouse T1R3 to antagonize the heterologously expressed mousesweet receptor’s response to a panel of sweeteners. Co-expressingthe non-taster allele of mT1R3 with human T1R2 yields afunctional sweet receptor that is sensitive to gurmarin, indicatingthat these allelic variations in mT1R3 does not affect gurmarinbinding. Studies with human-mouse chimeras of T1R3 indicatedthat the first 150 amino acids (aa) of T1R3 must be from mouse tomaintain sensitivity to gurmarin. Additional chimeras narrowedthe region of importance to aa 40-80 of mT1R3. Based on thecrystal structure of mGluR1, we created a homology model of theVenus Fly Trap Module of mT1R3. According to this model a41-66 aa loop (loop1) is present within the upper lobe1 of thereceptor’s cleft. In our model, gurmarin docks to the receptorwithin the open cleft of the VFTM, directly in contact with theupper lobe. The difference in the 3D shape of the correspondingloop1 of human T1R3 suggests that steric hindrance preventsgurmarin from binding to human T1R3’s VFTM cleft. Wehypothesize that gurmarin may inhibit activation of the sweetreceptor by preventing proper adoption of T1R3 VFTM closestate. In addition, analysis of the interactions in the docked modelbetween gurmarin and the receptor accord with previous workidentifying key aromatic residues necessary for gurmarinfunction. Finally, point mutants altered at residues of mouseT1R3 predicted to interact with gurmarin displayed reducedsensitivity to gurmarin in in-vitro assays.#P184 Poster session IV: Chemosensory transductionand perireceptor eventsEffect of inosine monophosphate (IMP) on taste perceptionof methionine and valine by miceYuko Murata 1 , Alexander A. Bachmanov 2 , Gary K. Beauchamp 21National Research Institute of Fisheries Science Yokohama, Japan,2Monell Chemical Senses Center Philadelphia, PA, USAIn vitro heterologous expression studies showed that most L-amino acids, including L-methionine (Met) and L-Valine (Val),activate the mouse T1R1+T1R3 receptor when they are mixedwith IMP. However, Met and Val differ in their ability to activatethe mouse T1R1+T1R3 receptor without IMP. While Metstrongly activates this receptor, Val evokes only negligibleactivation (Nelson et. al., 2002). The goal of our study was toexamine whether addition of IMP changes taste quality perceptionof Met and Val. We have addressed this question using aconditioned taste aversion (CTA) technique. Separate groups ofC57BL/6J mice were exposed to one of four conditioned stimuli(50 mM Met, 50 mM Met + 2.5 mM IMP, 50 mM Val or 50 mMVal + 2.5 mM IMP) or to water (control) and injected with LiClto form CTA. Conditioned mice were presented with five basictaste solutions, Met and Val, and their lick responses wererecorded. An aversion to Met generalized to quinine, while anaversion to Met+IMP generalized to Met, 150 mM sucrose, amixture of 50 mM MSG and 30 M amiloride (Ami; added toblock sodium taste) with or without 2.5 mM IMP (i.e.,MSG+IMP+Ami and MSG+Ami), but not quinine. An aversionto Val generalized to quinine, while an aversion to Val+IMPgeneralized to MSG+IMP+Ami and MSG+Ami, but not quinine.This suggests that addition of IMP changes the taste quality ofMet and Val in vivo, which is consistent with results of in vitroexperiments. Supported by Fisheries Research Agency(Yokohama, Japan) research grant (YM) and NIH grant DC00882 (GKB and AAB).#P185 Poster session IV: Chemosensory transductionand perireceptor eventsMitigation of irradiation effects on taste epithelium in theProtein Kinase C delta null mouseH.M. Nguyen 1 , M.E. Reyland 2 , L.A. Barlow 11Dept. of Cell & Developmental Biology, and The RockyMountain Taste and Smell Center, School of Medicine, Universityof Colorado Denver Aurora, CO, USA, 2 Dept. of CraniofacialBiology, School of Dental Medicine, University of ColoradoDenver Aurora, CO, USARadiotherapy for head and neck cancer can result in taste loss;yet how radiation influences taste is unknown. One idea is thatdisruption of taste cell renewal may be causal. Taste cell turnoverspans 10-14 days (Beidler and Smallman, 1965) driven byproduction of transit amplifying (TA) cells in or near taste budsfrom as-of-yet unidentified stem cells. We propose that taste lossafter irradiation is due to apoptosis of replenishing TA cells, andconsequent attrition of mature taste cells. In support of this, wefind that proliferating TA cells are absent at 3 days postirradiation (dpi) including cells in S (BrdU-IR) and M (phosphohistone3(pH3)-IR) phases, in fungiform (ffp) and circumvallate(cvp) papillae. Thus, one strategy for averting taste loss may be toreduce epithelial cell death, with the prediction that cell divisionwould not be interrupted. Protein kinase C delta (PKCd) is amultifunctional kinase, which positively regulates apoptosis.To test if radiation effects on taste epithelium are mitigated inPKCd-/- mice, the heads of wild type (WT) and PKCd-/- adultswere irradiated with a single 8Gy dose and lingual epitheliaexamined for BrdU- and pH3-IR at progressive dpi. As in ourinitial results, in ffp and cvp, BrdU-IR cells are absent at 3 dpi,increase at 5 dpi, then decrease after 9 dpi. Cells in M phase(pH3-IR) are missing at 3 and 5 dpi, reappear by 7 dpi, thendecrease after 9 dpi. By contrast, the proliferative profile ofirradiated PKCd-/- mice does not drop; BrdU- and pH3-IR cellsare present at 3 and 5 dpi and dividing cell number is dramaticallyhigher from 7-11 dpi compared with WT mice. Our data suggestthat PKCd is required for apoptotic cell death and/or repressesproliferation in irradiated taste epithelium.84 | AChemS Abstracts 2009

#P186 Poster session IV: Chemosensory transductionand perireceptor eventsEffect of Nicotinic Acetylcholine Receptor (nAChR)Blockers, Mecamylamine (Mec) and Dihydro-b-erthroidine(DH E) on the Chorda Tympani Responses to Nicotine inTRPM5 Knockout (KO) MiceAlbino J. Oliveira-Maia 1 , Tam-Hao T. Phan 2 , ShobhaMummalaneni 2 , Pamela Melone 2 , Miguel A. L. Nicolelis 1 ,Sidney A. Simon 1 , John A. DeSimone 2 , Vijay Lyall 21Department of Neurobiology, Duke University Medical CenterDurham, NC, USA, 2 Department of Physiology and Biophysics,Virginia Commonwealth University Richmond, VA, USAThe TRPM5 cation channel is an essential downstream signalingeffector in taste cells for bitter, sweet and umami tastetransduction. Accordingly, when the tongues of Trpm5 KO micewere stimulated with10 or 20 mM quinine (bitter stimuli) the CTresponses were not different from those of the rinse. However, arobust CT response was elicited by 10 and 20 mM nicotine, alsoreported as bitter by humans. The magnitude of the tonic CTresponse to nicotine in TRPM5 KO mice was 40% smaller thanthe response in the wildtype (WT) control mice, suggesting that60% of the CT response to nicotine is TRPM5-independent.To determine if the TRPM5-independent component of the CTresponse to nicotine is dependent upon the presence of nAChRs,we investigated the effect of the nAChR blockers Mec and DHbE(0.05 – 0.5 mM) on CT responses to nicotine in TRPM5 KO mice.Both Mec and DHbE inhibited the CT response to nicotine in adose-dependent manner. 0.3 mM Mec and 0.4 mM DHbEinhibited the CT response to 10 mM nicotine by 40% and 58%,respectively. Using a combination of 0.3 mM Mec and 0.4 mMDHbE further inhibited the CT response by 96%. At 20 mMnicotine Mec+DHbE inhibited the CT response to 20 mMnicotine by 84%. We conclude that nAChRs composed of a3, a4,2 and 4 may be responsible for the CT response in TRPM5 KOmice. The presence of a3, a4, 2 and 4 nAChR subunits was furtherconfirmed by RT-PCR with cDNA made from fungiform tastebuds derived from WT mice and using specific primers for theabove subunits.#P187 Poster session IV: Chemosensory transductionand perireceptor events1,3-N-Acetylglucosaminyltransferase 1 ( 3GnT1)regulates signaling in olfactory neuronsTimothy R. Henion, Gary A. SchwartingUniversity of Massachusetts Medical School Worcester, MA, USA3GnT1 is a glycosyltransferase that is highly expressed bysensory neurons in the mouse olfactory epithelium (OE). Wepreviously showed that 3GnT1 expression is required for properformation of connections between subsets of neurons in the OEand their targets in the main olfactory bulb (OB). P2 neurons failto form glomeruli in 3GnT1 null mice, while the positioning ofM72 glomeruli is displaced towards the rostral/medial OB. Thisphenotype is remarkably similar to defects reported for micedeficient in AC3, a heavily glycosylated adenylyl cyclase isoformthat determines intracellular cAMP levels and glomerularpositioning in the OB. The phenotypic similarities between thesemouse lines suggest that 3GnT1 influences on targeting could bemediated through direct glycosylation of AC3. We show herethat AC3 of wildtype mice strongly reacts with both theanti-lactosamine monoclonal antibody 1B2 and the poly-Nacetyllactosaminebinding lectin LEA. Western analysis of AC3isolated from olfactory cilia of 3GnT1 null mice shows a dramaticreduction in size, and a loss of 1B2 and LEA reactivity.Furthermore, AC3 protein expression overall is greatly reducedin the OE and the OB of 3GnT1 null mice, suggesting that theproper glycosylation of AC3 is required for its expression andfunction in olfactory neurons.#P188 Poster session IV: Chemosensory transductionand perireceptor eventsPenetrating the Permeability Barrier that SurroundsMouse Taste BudsElizabeth Pereira 1 , Robin Dando 1 , Nirupa Chaudhari 1,2 ,Stephen Roper 1,21Miller School of Medicine, University of Miami Miami, FL, USA,2Program in Neuroscience, University of Miami Miami, FL, USAAll epithelia contain specialized junctions between cells. Thesejunctions are formed by interacting membrane proteins and bycytoskeleton and extracellular matrix components. Proteins thatmake up junctions include claudins, occludins, tricellulin, andjunction adhesion molecules. In taste buds, tight junctions join theapical tips of taste cells and constitute an apical barrier.Apical tight junctions provide a selective barrier that separates themucosal surface of the tongue from the underlying basolateralspaces within the taste bud. Tight junctions are thought to limittastant (and drug) permeability into taste buds (Michlig et al2007). We have developed a simple assay for determining howwell compounds permeate into mouse taste buds (Pereira et alISOT 2008). Our assay uses lingual slices incubated in lipophilicor hydrophilic fluorescent dyes. Surprisingly, we discovered thatthe permeability barrier is not limited to apical tight junctions.Entire taste buds are surrounded by a permeability barrier. Here,our goal was to find methods to break down the barrier. We useda number of different treatments, including Ca 2+ -free solutions,Na caprate, verapamil, and C-terminal fragments of C. perfingens.However, dye penetration into taste buds was most reliablyachieved by briefly treating lingual slices with 75% DMSO. Wetested whether exposure to such high concentrations of DMSOaffected the physiology of taste bud cells. We measured Ca 2+responses of taste cells in lingual slice preparations (confocal Ca 2+imaging) before and after DMSO. DMSO did not compromisetaste- and depolarization-evoked Ca 2+ responses. Indeed,responses to bath-applied stimuli such as KCl were enhanced.These results show a quick and effective way to enhance drugpenetration into taste buds.P O S T E R SAbstracts | 85

#P189 Poster session IV: Chemosensory transductionand perireceptor eventsElectrophysiological Responses to Tactile Stimulation of theTongue in the Presence of Oils and Gustatory StimuliThomas C. Pritchard 1 , Erin N. Nedderman 1 , John Coupland 2 ,Ralph Norgren 11The Pennsylvania State University College of Medicine Hershey,PA, USA, 2 The Pennsylvania State University University Park,PA, USAFats and oils are highly preferred by humans and rats and arenecessary components of a balanced diet, yet little is known aboutthe sensory detection of lipids. The responses from individualaxons of the chorda tympani (CT) and lingual nerve (LN) wererecorded during separate and concurrent stimulation of thetongue with mineral oil (MO), corn oil (CO) and 25% emulsionsof each. Caseinate (1%) was the emulsifier. Gustatoryresponsiveness was tested with 0.3M sucrose, 0.1M NaCl, 0.01Mcitric acid, 0.003M QHCl, and 0.1M MSG. A motorized, rotarybrush was used for somatosensory stimulation of gustatory andtactile receptive fields on the anterior tongue. We hypothesizedthat the lubricating properties of the oils would modify the neuralresponses evoked by stroking the tongue with the brush. Datacollected from thermal fibers, unresponsive fibers, and those notfully tested were excluded. Based upon preliminary analysis,passive application of the oils and oil emulsions did not activateCT or LN axons. Tactile responses were reduced by 15% in thepresence of either MO or CO, but not by the oil emulsions. Inseveral instances, mechanical stimulation of the tongue caused atransient inhibition of taste-evoked responses in the CT. Similarly,in several fibers, application of sapid stimuli to the tongue alteredthe time course or effectiveness of tactile stimulation. Moredetailed analysis of the present data and, if need be, a differentexperimental design will be used to determine if mechanicalmodulation of gustatory responses is the basis for oral detectionof lipid stimuli.#P190 Poster session IV: Chemosensory transductionand perireceptor eventsOptimization of the production of recombinant brazzeinsecreted by the yeast pichia pastorisAntoine Rachid, Christine Belloir, Joëlle Chevalier, CatherineDesmetz, Marie-Louise Miller, Nicolas Poirier, Loïc BriandINRA, UMR 1129 FLAVIC Dijon, FranceBrazzein is a small (6.5 kDa), heat- and pH-stable sweet proteinoriginating from the fruit of Pentadiplandra brazzeana Baillon, aplant found in West Africa. Brazzein isolated from its naturalsource exists in two forms differing in sweetness intensity. Themajor form (54 amino acids, ~80%), called pGlu-bra, contains apyroglutamic acid (pGlu) at is N-terminus, while the minor form(53 amino acids, ~20%), called des-pGlu-bra, lacks the N-terminal pGlu. It has been reported that des-pGlu-bra is twice assweet as pGlu-bra. Heterologous expression of brazzein inbacteria is complicated by the presence of a pyroglutamic acid(pGlu) in the major form of brazzein. Here we report theheterologous expression of brazzein using the methylotrophicyeast Pichia pastoris as major form under the control of themethanol-inducible alcohol oxidase (AOX1) promoter. Brazzeinwas secreted into the extracellular medium using the alpha-factorpreprosequence peptide of Saccharomyces cerevisiae without theGlu-Ala-Glu-Ala spacer. We found that brazzein regularlyaccumulated in the culture medium reaching approximately 40 mgper liter of culture over an expression period of 6 days. Afterdialysis, the yeast culture filtrate containing recombinant brazzeinwas submitted to cation-exchange chromatography and twobrazzein isoforms were isolated. MALDI-TOF massspectrometry revealed that the first isoform was pGlu-bra, whilethe second isoform, called Gln-bra, was assigned to the samemolecule with a N-terminal glutamine residue instead of thepyroglutamic residue. 1D NMR spectroscopy revealed that bothbrazzein isoforms were properly refolded. Moreover, bothbrazzein isoforms were able to stimulate hT1R2/hT1R3 tastereceptor in agreement with their sweetness properties.#P191 Poster session IV: Chemosensory transductionand perireceptor eventsAutocrine Regulation of ATP Secretion in Mouse Taste BudsStephen D. Roper 1,2 , Yijen A. Huang 11Miller School of Medicine, University of Miami Miami, FL, USA,2Program in Neuroscience, University of Miami Miami, FL, USAReceptor (Type II) cells secrete ATP and stimulate adjacentPresynaptic (Type III) cells to release serotonin (5-HT, Huang etal, PNAS, 2007). We have shown that 5-HT mediates negativefeedback onto Receptor cells and inhibits ATP secretion (Huang& Roper, AChemS 2009). Here we examine the autocrine effectsof ATP back onto Receptor cells. Single Presynaptic and Receptorcells isolated from mouse circumvallate taste buds were loadedwith calcium indicator dye, Fura-2. When we bath-applied ATPonto isolated taste cells, Presynaptic and Receptor cells alikeshowed robust Ca 2+ responses. ATP-evoked Ca 2+ signals were notaffected when extracellular Ca 2+ was removed from the bath,indicating that responses were generated by intracellular Ca 2+release. Further, ATP-evoked Ca 2+ responses of Receptor cellswere abolished by MRS2179, a selective P2Y1 receptor antagonist.Thus, metabotropic P2Y, not ionotropic P2X purinoceptors aremainly responsible for the actions of ATP. Because Receptor cellswere excited by ATP, we tested whether ATP exerts positivefeedback (autocrine) during taste stimulation. We used ATPsensitiveand 5-HT-sensitive biosensor cells to detect taste-evokedtransmitter release from isolated taste buds. Indeed, ATP and 5-HT secretion were significantly decreased in the presence ofMRS2179 (10 µM). Moreover, Receptor cells isolated fromP2Y1/P2Y2 double knockout mice failed to respond to ATP andADP. These findings suggest that P2Y receptors, particularlyP2Y1, exert positive autocrine feedback during taste budsignaling. Taken together with findings described in Huang &Roper (AChemS 2009), these data show that complex cell-cellinteractions take place during taste stimulation. ATP exertspositive, and 5-HT exerts negative feedback onto Receptor cells.86 | AChemS Abstracts 2009

#P192 Poster session IV: Chemosensory transductionand perireceptor eventsAcidic substances added in the oral cavity reduce ourbitter taste sensation by pH-dependent inhibition ofhTAS2R responseTakanobu Sakurai 1,2 , Takumi Misaka 2 , Toshitada Nagai 2 , YoshiroIshimaru 2 , Shinji Matsuo 1 , Tomiko Asakura 2 , Keiko Abe 21General Research Institute of Food Science and Technology,Nissin Foods Holdings Co., Ltd. Shiga, Japan, 2 Department ofApplied Biological Chemistry, Graduate School of Agriculturaland Life Sciences, The University of Tokyo Tokyo, JapanSome acidic peptides are known to reduce our bitter tastesensation, although the mechanism remains to be elucidated.The recent progress in taste molecular biology has revealed thatG protein-coupled receptor members of the TAS2R family actto receive bitter tastants; 25 members have been identifiedas bitter taste receptors including hTAS2R16 that responds tob-glucopyranosides. We investigated the bitterness-maskingeffects of acidic dipeptides by calcium imaging analysis usingHEK293T cells that transiently expressed hTAS2R16 along withG 16gust44. Salicin, a cognate bitter tasting ligand, was used in thepresence or absence of acidic dipeptides, with the result that acidicdipeptides significantly reduced the receptor response to thisligand. Interestingly, a variety of acidic substances includingamino, organic and inorganic acids as well inhibited the responseof hTAS2R16 to salicin, while no such effect was observed withneutral peptides and amino acid, and as well as acidic amino acidsalts. The inhibition took place depending on the pH values as aresult of the addition of acids but not on their concentrations.We also confirmed the inhibition of hTAS2R38 response toN-phenylthiourea and 6-propyl-2-thiouracil at low pH. Ourresults suggest that the reduction of our bitter taste sensation byacidic dipeptides in particular and sour taste substances in generalcan be attributed to their inhibitory effects on hTASA2Rmolecules and also that the receptor-environmental pH in theoral cavity is a critical factor responsible for this sensory event.Supported by Research and Development Program forNew Bio-industry Initiatives.#P193 Poster session IV: Chemosensory transductionand perireceptor eventsUnraveling the Signal Transduction Cascade Mediated by theOlfactory Receptor hOR51E2 in Prostate Cancer CellsJennifer Spehr, Markus Osterloh, Weiyi Zhang, Lian Gelis, HannsHatt, Eva M. NeuhausDept. of Cellular Physiology, Ruhr-University Bochum Bochum,GermanyOlfactory receptors (ORs) are expressed not only in the sensoryneurons of the olfactory epithelium but also in various othertissues. The functions of ORs in these tissues are largelyunknown. We previously reported that the human OR51E2,which is endogenously overexpressed in prostate cancer cells, canbe activated by androstenone derivates as well as the odorantionone. We could also show that exposure to ionone resulted ininhibition of cell proliferation as well as induction of apoptosis.Here, we characterized the signal transduction mechanisminduced by activation of OR51E2 in LNCaP cells (prostate cancercell line) using a combination of calcium imaging, patch clamp andbiochemical techniques. Ionone stimulation leads to an increase ofintracellular calcium, which at least in part depends onextracellular calcium. Electrophysiological measurements revealedan ionone dependent opening of a calcium conductance in theplasma membrane. Further biophysical and pharmacologicalanalysis identified TRPV6 as transduction channels, a finding thatwas confirmed by RNAi experiments. The expression of TRPV6in prostate cancer cells has been described before but the functionas well as the activation mechanism was still elusive. Currently, weinvestigate how activation of the OR51E2 leads to an opening ofTRPV6 channels. In summary we report the first endogenouslyexpressed OR that couples to a signal transduction cascadedifferent from the one used in olfactory sensory neurons. Namelywe show that OR activation leads to an opening of TRPV6channels.#P194 Poster session IV: Chemosensory transductionand perireceptor eventsExpression and Functionality of Oxytocin Receptor inMouse Taste CellsMichael Sinclair 1 , Gennady Dvoryanchikov 2 , KatsuhikoNishimori 3 , Nirupa Chaudhari 1,21Program in Neurosciences, University of Miami Miller School ofMedicine Miami, FL, USA, 2 Department of Physiology andBiophysics, University of Miami Miller School of Medicine Miami,FL, USA, 3 Department of Molecular and Cell Biology, GraduateSchool of Agricultural Science,Tohoku University Miyagi 981-8555, JapanOxytocin (Oxt), in addition to its effects on reproduction andcertain behaviors, may also influence taste and feeding. Forexample, Oxt -/- mice overconsume sweet solutions regardless ofcaloric content. And mice lacking the cognate receptor, i.e. Oxtr -/- ,are obese. We asked if Oxtr is expressed and functional in mousetaste buds. Using RT-PCR, we detected Oxtr mRNA in vallate,foliate, palatal and fungiform taste buds. In vallate taste buds,Oxtr mRNA is 1000-fold less abundant than b-actin mRNA.Immunocytochemistry revealed that Oxtr is expressed in cells thatare neither Type II/Receptor cells nor GAD-expressing TypeIII/Presynaptic cells. In taste buds from Oxtr-YFP(Venus) knockinmice also, we found that YFP-labeled (that is, Oxtr-expressing)taste cells did not overlap with PLC 2 immunofluorescence. Thus,Oxtr expression might be limited to Type I taste cells. RT-PCR onisolated single taste cells confirmed that Oxtr is expressed only inType I/glial-like (NTPDase2-expressing) cells. Using Fura-2 Ca 2+imaging, we observed dose-dependent increases of intracellular[Ca 2+ ] in vallate taste cells and this was attributed to release fromstores. Responses were detectable at 10 nM Oxt, saturated at1mM, and displayed an EC 50 of ~30 nM, similar to the sensitivityof uterine smooth muscle, a known target of Oxt. The Oxtrantagonist, L-371,257, significantly decreased the Ca 2+ response.None of the isolated cells that responded to Oxt expressedPLCb2. In sum, our data indicate that Oxtr is expressed in asubset of taste cells that are likely Type I/glial-like, and that thesecells can respond to physiological concentrations of Oxt via Oxtr.Therefore, it is possible that Oxt may exert at least some of itseffects on taste and feeding at the level of the taste bud.P O S T E R SAbstracts | 87

#P195 Poster session IV: Chemosensory transductionand perireceptor eventsInhibition of bitter taste receptorsJay Slack 1 , Anne Brockhoff 2 , Batram Claudia 2 , Susann Menzel 2 ,Caroline Sonnabend 2 , Maik Behrens 2 , Nicole Brune 1 , IoanaUngureanu 1 , Christopher Simons 1 , Wolfgang Meyerhof 21Givaudan Flavors Corp Cincinnati, OH, USA, 2 German Instituteof Human Nutrition Potsdam-Rehbruecke Potsdam-Rehbrueke,GermanyIn humans, bitter taste is mediated by ~25 G protein-coupledreceptors of the hTAS2R family. For most TAS2Rs, severalcognate agonists have been identified suggesting that the TAS2Rspossess broad ligand spectra. Specific TAS2R inhibitors wouldallow for pharmacological analysis of the bitter response in vivoand reduction of unwanted bitterness in food and medicine. Byscreening a chemical compound library in cell-based receptorassays we found that 4-(1,1,2-trimethyl cyclopentanoyl-) butanoicacid (GR-81-3727) concentration-dependently blocked activationof hTAS2R44 by the sulfonyl amides saccharin and acesulfame-K,as well as by several other agonists. GR-81-3727 also abolished,with distinct potencies, agonist-induced responses of cellsexpressing various other hTAS2Rs, including hTAS2R43, which ishighly similar to hTAS2R44 and is also activated by thesulfonamides. In human sensory trials, GR-81-3727 effectivelyreduced the bitterness associated with ace-K and saccharin,indicating that it has physiological efficacy as a bitter tasteinhibitor. In vitro analyses employing chimeric receptors betweenhTASR44 and hTAS2R46 revealed that GR-81-3727 caused rightwardshifts of concentration-response functions and likely acts asa competitive antagonist. Notably, we also discovered that GR-81-3727 acted as an agonist at one hTAS2R. In similarexperiments, we also identified additional TAS2R antagonists withproperties similar to those of GR-81-3727. Together, our datademonstrate that the property of GR-81-3727 to interact withmultiple bitter receptors is a feature it shares with numerousTAS2R agonists. Our results also suggest unexpectedly complexinteractions between chemicals released from food in the mouthduring a meal with the family of TAS2Rs to elicit the bitterresponse.#P196 Poster session IV: Chemosensory transductionand perireceptor eventsSolitary chemosensory cells (SCCs) in the pancreasMarco Tizzano 1,2 , Zaza Kokrashvili 4 , Bedrich Mosinger 4 ,Sukumar Vijayaraghavan 3,2 , Robert F Margolskee 4 ,Thomas E Finger 1,21Cell & Development Biology, Univ. of Colorado at DenverAurora, CO, USA, 2 Rocky Mountain Taste & Smell CenterAurora, CO, USA, 3 Physiology and Biophysics, Univ. of Coloradoat Denver Aurora, CO, USA, 4 Department of Neuroscience,Mount Sinai School of Medicine New York, NY, USASolitary chemoreceptor cells (SCCs) are specialized cells of thegastrointestinal and respiratory tracts which detect and respond toa variety of compounds, including nutrients and irritants. Forexample, SCCs of the gut detect glucose by transductionmechanisms similar to those used by taste cells of the tongue toregulate secretion of insulin and hormones that affect appetite(Margolskee et al, 2007; Jang et al, 2007). In contrast, airway SCCsrespond to irritants and certain bitter substances (Lin et al. 2008;Gulbransen et al 2008). These diverse SCCs express manymarkers typical of taste cells including the G-protein gustducin,PLC 2, TrpM5, IP3R3, and bitter (T2Rs) and sweet/umamireceptors (T1Rs). The major pancreatic excretory ducts contain alarge number of specialized epithelial cells, named brush cells,which express gustducin (Hofer D & Drenckhahn D, 1998). Thefunction of pancreatic SCCs is unknown. Here we report thatmany of the SCCs in the pancreatic excretory ducts also expressGFP driven by the promoter for choline acetyltransferase (ChAT)or by the promoter for TrpM5. Further, TrpM5GFP+ SCCs aredetected in gall bladder, common bile duct and papilla of Vaterwhich sits at the exit of the pancreatic duct into the intestine.Many of the GFP+ SCCs also express gustducin and are sparselyinnervated by peptidergic (CGRP) sensory fibers. These findingssuggest that SCCs may release acetylcholine upon stimulation,thereby affecting the sensory afferents and/or surroundingtissues. Thus, chemosensory control of pancreatic secretion mightoccur via two independent mechanisms: hormonal (from the gut)and neural/paracrine from local SCCs. The SCCs associated withthe pancreatic ducts and papilla of Vater may providechemoreceptive feedback to regulate pancreatic secretions.#P197 Poster session IV: Chemosensory transductionand perireceptor eventsThe prenyl binding protein PrBP/d impedes trafficking ofG olf in olfactory sensory neurons (OSNs)Mavis A. Irwin 1 , Houbin Zhang 2 , Michelle Stamm 1 , WolfgangBaehr 2 , Mary Lucero 11University of Utah, Department of Physiology, NeuroscienceProgram Salt Lake City, UT, USA, 2 University of Utah,Department of Ophthalmology Salt Lake City, UT, USAThe ubiquitous prenyl binding protein, termed PrBP/d, isimportant in processing and targeting of prenylated proteins.We recently deleted the murine Pde6d gene (encoding PrBP/d),and observed that transport of GRK1 and PDE6 from theendoplasmic reticulum to the cilium of photoreceptors wasdisrupted and led to severe alterations in photoreceptorphysiology 1 . We used Pde6d -/- mice to identify the role of PrBP/din olfactory sensory neurons (OSNs). We found a dramaticdecrease in immunoreactivity for G olf in the cilia of Pde6d -/-OSNs but normal localization of ACIII. Initial behavioral testsshowed that most Pde6d -/- mice were capable of discriminatingbetween R and S carvone however investigation time wasreduced. Despite modest behavioral changes, electrical responsesto odorants were significantly reduced in Pde6d -/- mice. Peakamplitudes of electro-olfactograms (EOGs) of the odorantresponses to 2-heptanone, n-amyl acetate, and (-)-menthone inPde6d -/- mice (ages 16, 20, 23, and 28 months) were only 23± 10%of EOG responses in approximately age-matched control mice(4 knock out and 4 wild type; Student’s t-test p

#P198 Poster session IV: Chemosensory transductionand perireceptor eventsOdor-stimulated phosphoinositide signaling in mammalianolfactory receptor neuronsKatharina Klasen 1 , Elizabeth A. Corey 1 , Christian H. Wetzel 2 ,Hanns Hatt 2 , Barry W. Ache 11Whitney Laboratory, Center for Smell and Taste, McKnight BrainInstitute, University of Florida Gainesville, FL, USA,2Department of Cell Physiology, Ruhr-University BochumBochum, GermanyOdors can modulate rat olfactory receptor neurons (ORNs) in aphosphoinositide (PI)-dependent manner (Spehr et al., 2002). Tosupport the assumption that odors indeed activate PI signaling, wecreated an adenoviral vector carrying two different PI activitymarkers, the pleckstrin homology (PH) domain of phospholipaseC 1 (PLC 1) for monitoring the activity of PLC and the PHdomain of the general receptor of phosphoinositides (GRP1) formonitoring the activity of phosphoinositide-3-kinase (PI3K) inthe dendritic knobs of mouse ORNs in vivo. Two differentcomplex odors (Henkel 100, Symrise 100) caused translocation ofPI3K and PLC in 9.6% and 17.4%, respectively, of the ORNstested. We subsequently used a phospholipid overlay assay andELISA to measure odor stimulation of PLC and PI3K in mouseand rat olfactory ciliary membranes in vitro. The same odormixtures could activate PLC and PI3K as fast as 2 sec of odorstimulation, with PLC being activated more robustly. Odordependentactivation of PLC and PI3K could be blocked by PLCandPI3K-specific inhibitors, respectively (U73122, Edelfosine,LY294002). These results collectively provide compelling evidencefor the presence of PI signaling in the transduction compartmentof mammalian ORNs and suggest that odors can activate bothPLC- and PI3K-mediated signaling sufficiently fast to account formodulation of the electrophysiological output of the cells.HEK-293 cells revealed channel properties similar to those of thenative calcium-activated chloride channel recorded from OSNmembrane patches. Together, we propose that TMEM16B is amajor component of the olfactory calcium-activated chloridechannel.#P200 Poster session IV: Chemosensory transductionand perireceptor eventsWITHDRAWNP O S T E R S#P199 Poster session IV: Chemosensory transductionand perireceptor eventsA Proteomic Screen of Mouse Cilial MembranesReveals TMEM16B as an Olfactory Calcium-ActivatedChloride ChannelAaron B Stephan 1 , Eleen Y Shum 1 , Sarah Hirsh 1 , Katherine DCygnar 1 , Haiqing Zhao 1 , Johannes Reisert 21Johns Hopkins University Baltimore, MD, USA, 2 MonellChemical Senses Center Philadelphia, PA, USAA major amplification step in olfactory signal transduction is theefflux of chloride ions in response to elevated calciumconcentration in the olfactory sensory neuron (OSN) cilia.However, the molecular identity of the olfactory calciumactivatedchloride channel remains elusive. To identify thischannel, we isolated OSN cilial membranes and analyzed theproteins in the preparation by mass spectrometry. We identified53 proteins by two or more peptides as being present, includingall of the known signal transduction components. TMEM16B andCLIC6 were the only two proteins found to be putative chloridechannels. While CLIC6 was found to originate from supportingcells, TMEM16B mRNA localized specifically to olfactorysensory neurons by in situ hybridization. Transfection of HEK-293 cells with C-terminal GFP-tagged TMEM16B showed plasmamembrane localization. Expressing this construct using anadenoviral vector, TMEM16B::GFP fusion protein localized tothe OSN cilia. Patch-clamp analysis of TMEM16B expressed in#P201 Poster session IV: Chemosensory transductionand perireceptor eventsTRPM5 Expressed in Solitary Chemosensory Cells is Involvedin Regulating Chemical Access to the Vomeronasal OrganKurt Krosnowski, Nejat Merdato, Tatsuya Ogura, Weihong LinUniversity of Maryland Baltimore County Catonsville, MD, USAThe mouse vomeronasal organ (VNO), a peripheral sensoryorgan, detects semiochemicals. Complex stimuli containingsemiochemicals are drawn into the lumen of the VNO, some ofwhich may be contaminated by irritating and harmfulenvironmental substances. Mechanisms that monitor and controlchemical access to the VNO are not well understood. In theVNO, the majority of the solitary chemosensory cells (SCCs)expressing transient receptor potential channel M5 (TRPM5) islocalized in the anterior vomeronasal duct. Previous research hasshown that SCCs respond to stimuli known to activate thetrigeminal system (Ogura et al ISOT abstract 2008). Wehypothesize that TRPM5 in SCCs plays an important role incontrolling chemical access to the VNO. To monitor chemicalaccess to the VNO we exposed both wild type (WT) and TRPM5deficient (TRPM5KO) mice to chemical stimuli mixed with aAbstracts | 89

hodamine dye and measured the fluorescent intensity in theVNO. In WT mice the fluorescent intensity of the VNO wasnegatively correlated with the concentrations of the exposedirritants indicating the stronger the irritants the lesser amountdrawn into the VNO. In KO mice the fluorescent intensity wassignificantly higher for both control and irritant stimuli indicatinggreater chemical access to the VNO. In addition the pH of thesolution affected chemical access to the VNO, decreasing as thepH deviates from neutral. This pH dependent pattern is distortedin TRPM5KO mice. Our data strongly indicate that TRPM5expressed in SCCs of the VNO is involved in monitoring andcontrolling chemical access to the VNO.#P202 Poster session IV: Chemosensory transductionand perireceptor eventsTransient receptor potential V1 is directly activated bynickel ionsMatthias Luebbert 1 , Debbie Radtke 1,2 , Hanns Hatt 1 ,Christian H. Wetzel 11Department of Cellular Physiology Ruhr University BochumBochum, Germany, 2 Ruhr University Research School Bochum,GermanyTRPV1 is a member of the transient receptor potential (TRP)family of cation channels. It is expressed in sensory neurons oftrigeminal and dorsal root ganglions, as well as in a wide range ofnon neuronal tissues, including cells of the immune system. As apolymodal receptor, TRPV1 can be activated by various chemicaland physical stimuli, including divalent cations in concentrations>10 mM. Searching for further activators and modulators ofTRPV1, we were interested in the effect of Ni 2+ ions (NiSO 4 ),known to induce allergic contact dermatitis. Using Ca 2+ -imagingand whole-cell voltage-clamp recordings we observed thatmicromolar doses of NiSO 4 induced Ca 2+ transients in culturedcapsaicin-sensitive trigeminal neurons of mice. Moreover NiSO 4led to an activation of recombinant rat and human TRPV1heterologously expressed in CHO-cells, inducing significantoutwardly rectifying currents. Outside out recordings revealed anincrease in open probability paralleled by a decrease in singlechannelconductance. Both events resulted in an increased netactivity of TRPV1 which became manifest in macroscopiccurrents. The effect of Ni 2+ on capsaicin-induced currentsdepended on the capsaicin concentration. Outward currentsinduced by low doses of capsaicin were sensitized by NiSO 4 inlow concentrations, whereas currents induced by higher doses ofcapsaicin were inhibited. Using TRPV1-mutants with specificpoint mutations, we identified several positively charged aminoacids localized at the channels pore region which are apparentlyinvolved in the TRPV1 activation by Ni 2+ . Future experimentswill focus on the detailed molecular mechanisms of TRPV1activation and modulation by Ni 2+ and the impact of TRPV1 inthe development of pathophysiological changes in neuronal andnon-neuronal tissues.#P203 Poster session IV: Chemosensory transductionand perireceptor eventsCetylpyridinium Chloride Effects on Sodium and PotassiumTaste Stimulus Sensing in HamsterClara C. McClenon, Brooke L. Reidy, Victoria M. Stevens, RobertE. StewartWashington and Lee University Lexington, VA, USAWe sought to obtain neuropharmacological evidence for theexistence of a general salt-sensing pathway in taste receptor cellsof the hamster anterior tongue. Previous work has suggested thatsalty taste in rat depends partly on detection of sodium andpotassium by a variant form of the type I vanilloid receptor(VR1). We recorded integrated hamster chorda tympani nervetaste responses to sodium and potassium solutions (100 and 250mM) in the presence and absence of VR1 agonist-antagonistligands cetylpyridinium chloride (CPC) and SB-366791. Lingualapplication of CPC modestly, but significantly, inhibited chordatympani nerve taste responses to salts of sodium and potassium ina concentration-dependent, reversible manner. While 2 and 5 mMCPC caused significant suppression of 100 and 250 mM sodiumchloride (NaCl), sodium gluconate (NaGlu), and potassiumresponses (KCl) (ts ³ -.7.08, ps

eta, ENAC gamma), b-actin, PLC-b 2 , and tryptophanhydroxylase II (TPH) II mRNA, which were detected byRT-PCR, indicating expression of ENAC delta in different tastecell types. Immunoprecipitation - Western blot analysisdemonstrated protein-protein interaction among ENACsubtypes. Antibody capture PCR has the potential enriching cellsexpressing a particular protein for studies to explore theheterogeneity of cells expressing the same gene. It will also findapplication for studies of taste cell development, proliferation,differentiation and function in an in vitro preparation.#P205 Poster session IV: Chemosensory transductionand perireceptor eventsDirect evidence of the role of TRPM5 in bitter transduction inenteroendocrine cellsBhavik P. Shah 1,2 , Pin Liu 1,2 , Tian Yu 1,2 , Dane R. Hansen 1,2 ,Timothy A. Gilbertson 1,21Department of biology, Utah State University logan, UT,USA, 2 Center for Advanced Nutrition, Utah State Universitylogan, UT, USAEnteroendocrine cells (EECs) in the GI tract have been shown toexpress members of the bitter (T2R) taste receptor family and torelease satiety hormones like CCK and GLP-1 in response tobitter stimuli. Moreover, EECs express all the signalingcomponents identified in Type II taste receptor cells includingalpha gustducin, PLC-ß2 and TRPM5. While the role of TRPM5in bitter taste transduction is unequivocal, bitter-activated TRPM5currents have never been recorded in native cells. In the currentstudy, we have used the enteroendocrine cell line STC-1 toelucidate the bitter transduction pathway. To explore functionalresponses to bitter compounds in STC-1 cells, we have used patchclamping and ratiometric Ca 2+ imaging. Denatonium benzoate(DB) depolarized STC-1 cells and this depolarization wassignificantly reduced in absence of extracellular sodium ions. DBalso elicited rapid, Na + dependent inward currents at -100 mV. Ionsubstitution experiments revealed that these DB-induced currentswere carried by monovalent cations. DB-induced inward currentswere greatly reduced when upstream proteins like G proteins andPLC were blocked with GDP-ß-S and U73122, respectively,implying that these inward currents are activated downstream ofG proteins and PLC. DB-induced inward currents were inhibitedby the TRPM5 blocker, triphenylphosphine oxide (TPPO, 100µM) and were significantly reduced when expression of TRPM5was knocked down using RNA interference. These results areconsistent with a role of TRPM5 in bitter transduction.Consistent with these electrophysiological experiments, similarresults were found using fura-2 based calcium imaging tocharacterize the role of TRPM5 in the generation of bitterinducedchanges in intracellular calcium in EECs.#P206 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisATP Promotes Proliferation of Olfactory Sensory Neuron(OSN) and Sustentacular Progenitor Cells in Adult MouseOlfactory Epithelium (OE)Colleen C. Hegg, Cuihong JiaMichigan State University East Lansing, MI, USAExtracellular ATP exerts multiple neurotrophic actions in theolfactory system including the synthesis and release of growthfactors and cell proliferation, but the role of ATP in celldifferentiation is unknown. We hypothesized ATP could induceproliferation of OSN and sustentacular progenitor cells. AdultSwiss Webster mice were intranasally instilled with ATP (200 µM)or vehicle. After three BrdU injections (60 mg/kg ip) between 42-46 hours, tissue was collected at 2, 7 or 14 days after ATPinstillation. ATP significantly increased BrdU+ cells compared tovehicle controls by 125, 49 and 46 % at 2, 7 and 14 days (p0.5), indicating ATP produces atransient sustained increase in proliferation. We counted BrdU+cells in the apical sustentacular cell layer, the middle OSN layerand the basal cell layer. At 2 days, 97% of total ATP-inducedBrdU+ cells were in the basal layer and BrdU+ cells co-localizedwith the neuronal progenitor marker MASH1, but not theimmature neuronal marker GAP43. At 7 days, ATP significantlyincreased BrdU+ cells v. control in the apical and basal layers(3.4 v. 1.4 and 47.2 v. 32.9 BrdU+ cells/mm OE, p

enantiomer counterparts before and after the conditioning phase.In support of the previous study, there was a trend ofimprovement in enantiomer discrimination at post- relative topre-conditioning (P = 0.15). Importantly, increased enantiomerdiscrimination was significantly associated with anxiety (r = 0.38,P = 0.05) and perceived control of threat-relevant situations(r = -0.42, P = 0.03). That anxiety in this high-functioningnonclinical sample enhances odor discrimination learning suggeststhat non-clinical anxiety facilitates emotional learning via aversiveconditioning, thereby enhancing perceptual discrimination.This mechanism may serve to compensate for hyper-arousal andexcessive sensitivity to threat in anxiety, preserving the cognitiveand social functions of these individuals. Further evidence is beingcollected with measures of brain event-related potentials andautonomic responses.#P208 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisExpansion, Engraftment and Multi-Lineage Potency of MouseNeonatal Olfactory NeurospheresRichard C. Krolewski, James E. SchwobDepartment of Anatomy & Cellular Biology, Tufts UniversitySchool of Medicine Boston, MA, USAThe olfactory mucosa (OM) of humans and rodents exhibitsongoing neurogenesis and epithelial reconstitution followinginjury and may have potential for cell-based therapies.Unfortunately, conventional 2-D cultures of OM have limitedpotency following transplantation. The precedent set by CNSstem cell neurospheres have led us to investigate the use of a 3-Dolfactory neurosphere (ONS) culture system in which OMharvested from neonates was used as a proxy for stem andprogenitor activity. In our hands, ONS are comprised of multiple,marker-defined cell types as well as proliferating cells like thosefound in OE, confirming previous work (Barraud 2007). ONSwere passaged and exposed to varying growth factors and mediaconditions to determine their effects on expansion and renewal.Culture of passaged ONS in NIH3T3–conditioned mediaincreases the number of secondary spheres suggesting thatexpansion of ONS is driven by selected components of the culturemedia. To test the engraftment potential of ONS–derived cells,OM from constitutive GFP–expressing neonatal mice wasdissociated, cultured for 8 DIV as ONS and infused into the nasalcavity of host animals 1 day after exposure to the olfactotoxinmethyl bromide. At two weeks after transplantation, ONSderivedcells have engrafted into the host, are integrated in theregenerating olfactory epithelium and formed colonies. Thedonor–derived colonies are composed of multiple marker– andmorphology–defined OE cell types, demonstrating that culture asONS maintains the capacity for engraftment and themultipotency of ONS–derived cells. These data imply that therecapitulation of the rich milieu of inherent cell state, cell-to-cellcommunication, and growth factor influences are required tomaintain transplantation potential.#P209 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisComparison of incidental and intentional learning of olfactoryand visual stimuliPer Møller 1 , Dag Piper 2 , Ditte Hartvig 1 , Egon P Köster 11University of Copenhagen Frederiksberg, Denmark, 2 SymriseGermany Holzminden, GermanyObjective: To investigate if memories of incidentally andintentionally learned olfactory and visual stimuli differ withrespect to modality, mode of learning, gender and age. Methods:One hundred and seventeen young and 114 elderdy Ssparticipated in the experiment which had 2 sessions on 2 separatedays. Stimuli consisted of 12 odorants and 12 images of objectsemanating the odorants used. Half of each set of 12 stimuli werepleasant and the other half less pleasant. Young and elderly Sswere divided into two groups who learned the visual andolfactory stimuli to be remembered either incidentally orintentionally. Each of the learning groups were split into 4 groupsin which the olfactory and visual stimuli were either congruent orincongruent with respect to pleasantness. In the first task Ssevaluated pleasantness of 6 odours and 6 images. In the memorytest which followed after 5 min, the stimuli evaluated forpleasantness in the first task served as targets and the other 6odours and 6 images served as distractors. On day 2 Ss performed3 tasks: discrimination of odours and images used in the memorytest, a congruency test where each odour was presented with thetwo corresponding images and the task was to pair the odour withone of the images and vice versa for images and a hedonic test ofall 24 stimuli. Results and conclusions: Overall, there is nodifference in memory of incidentally and intentionally learnedstimuli and there is no difference between men and women.Young Ss, however, remember the stimuli significantly better thanelderly Ss (p

presented in a recognition memory paradigm were analyzedindependently. We used a Generalized Linear Model approachand logistic regression to predict recognition memoryperformance. The probability of correctly remembering an “old”odor was very strongly predicted by consistent odor labeling.Correctly categorizing “new” odors was best predicted by acombination of two predictors- accuracy of odor identificationand general memory performance across the “old” odors. It isproposed that odor knowledge (represented statistically as theinteraction of the individual and an odor stimulus) has a criticalinfluence on recognition memory performance.#P211 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisEmbryonic Chicks Can Learn the Scent of a Putative PredatorDaisy M. Yuhas, Emma L. Stanley, Julie C. HagelinDepartment of Biology, Swarthmore College Swarthmore,PA, USAResearch on the response of birds to the scent of predators isscarce, as are studies of avian chemosensory learning that occursin ovo. We incubated domestic chicken eggs (Gallus gallusdomesticus) in three different odor environments: (1) putativepredator odor (fox urine), (2) novel odor (vanilla), or (3) no odorcontrol. After hatching we measured the response of all chicks tothe aforementioned odors via two methods. The first measuredthe degree to which a chick in the hand roused from sleep whenexposed to odors (a simple discrimination test, Porter et al. 1999).The second involved recording the movement of pairs of chicksplaced in an unfamiliar arena and exposed to different odorconditions (a test of odor familiarity; Jones et al. 2002). Threeresults were notable. First, birds in the hand showed strongevidence of discrimination between all scents (35

ain region was isolated. Then, Cy3 labeled cRNA washybridized to whole rat genome chips. Out of 28,142 genespresent in each brain region, 251 (PBN), 113 (CeA/BLA), and103 (LH) showed up or down regulation of at least 2 fold and ap value ≤ 0.05. When considering only p values ≤ 0.001, thenumber of differentially expressed genes in PBN, amygdala, andLH decreased to 37, 27, and 22, respectively. Relative to controlanimals, CTA acquisition altered the expression of variouspeptides, transcription factors, phosphatases, kinases, receptorsand ion channels. Directional change in expression of subsets ofgenes was confirmed using quantitative real-time RT-PCR. Thepresent data provide a starting point for understanding geneexpression specific to gustatory and aversive visceral stimulation,as well as learning dependent modulation of gustatory palatability.#P214 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisExpression of Transient Receptor Potential (TRP) Channelsin the Mouse Main Olfactory Bulb (MOB)Hong-Wei Dong 1 , Sheng-Yuan Ding 2 , Qiang Nai 1 ,Fu-Ming Zhou 2 , Matthew Ennis 11Dept, Anat &Neurobiology, University of Tennessee, HSCMemphis, TN, USA, 2 Dept. Pharmacology, University ofTennessee, HSC Memphis, TN, USATRP channels are a large family of cation channels with widedistribution in the CNS. TRP channels are involved in sensoryprocessing in the visual, gustatory, olfactory, auditory andsomatosensory pathways. Currently, 28 TRP gene subtypes havebeen identified and subdivided into 6 families (TRPC1-7, TRPV1-6, TRPM1-8, TRPP2-3, 5, TRPML1-3 and TRPA2). The MOBhas been reported to express several TRP channel subtypes.However, the full expression profile of the TRP channel family inthe MOB has not been investigated, and very little is known aboutTRP channel expression in different MOB cell types. In presentstudy, we employed MOB tissue and single-cell RT-PCR methodsto investigate the expression of 28 TRP channel mRNAs in themouse MOB. Our results showed that TRPC1-7, TRPV2, 4,TRPM2-4, 6-8, TRPP2-3, 5 TRPML1-2 and TRPA2 mRNA wereexpressed in the MOB. To date, TRPC4-5 were detected inelectrophysiologically identified external cells and periglomerularcells whereas TRPC3, TRPC5, TRPV4 and TRPM2-3, 7-8 weredetected in electrophysiologically identified mitral cells.#P215 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisCholinergic modulation of glomerular circuitsShaolin Liu, Michael T. ShipleyUniversity of Maryland School of Medicine Baltimore, MD, USAThe olfactory bulb receives cholinergic (ACh) afferents from thebasal forebrain. These inputs are activated in a behavioral statedependentmanner. There are open questions about the impact ofACh inputs, particularly at the level of glomerular circuits. ONsynapses activate external tufted (ET) cells, which strongly exciteGABAergic periglomerular (PG) cells. PG cells providepresynaptic inhibition of ON terminals, postsynaptic inhibitionto MT cells as well as feedback inhibition to ET cells. Thusintraglomerular circuits generate inhibition at several points toshape the transfer of sensory signals to output neurons.With GABA A and GABA B Rs blocked, either nicotine (N)or a muscarinic (M) receptor agonist, milameline, significantlyreduced spontaneous EPSCs in PG but not ET cells, indicatingthat ACh suppresses ET cell excitation of PG cells via both Nand M ACh receptors. With fast glutamate Rs blocked,carbamylcholine, which activates both N and M receptors,significantly enhanced spontaneous IPSCs in both ET and PGcells. Scopolamine blocked and milameline replicated these effectsindicating that activation of M receptors increases intraglomerularrelease of GABA. ACh appears to reduce ET cell excitatory driveon PG cells, yet increases PG cell release of GABA. We areinvestigating whether ACh increases PG cell GABA release byaction potential-dependent/-independent mechanisms. Increasedintraglomerular GABA release may presynaptically inhibit ONinputs via GABA B receptors and postsynaptically inhibit MToutput firing via GABA A receptors. Behavioral state-dependentactivation of cholinergic inputs might contribute to increasedcontrast among glomeruli differentially activated by sensorysignals.#P216 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisSynchronization of spike activity in tufted cells of mouseolfactory bulbGraeme Lowe, Jie MaMonell Chemical Senses Center Philadelphia, PA, USASynchronization of principal cell spiking in the olfactory bulb isproposed to play a role in odor coding. Synchrony occurs inmitral cells linked to the same glomerulus, but has not beenanalyzed in tufted cells. We recorded spontaneous spiking frommitral and tufted cell pairs in mouse olfactory bulb slices andperformed cross correlation analyses on spike trains. Synchronousbursting and spiking were manifested as broad and narrow peaksin spike cross-correlograms from mitral-mitral, mitral-tufted andtufted-tufted pairs linked to the same glomerulus, but not todifferent glomeruli. Slow EPSCs were synchronized in mitraltuftedand tufted-tufted pairs linked to the same glomerulus.Spike synchrony was uncorrelated with burst synchrony,suggesting independent synchronization mechanisms. On average,spike synchrony was stronger and spike lags shorter in tuftedtufted,than in mitral-tufted or mitral-mitral pairs. All paircombinations exhibited electrical coupling, with largest meancoupling coefficient in tufted-tufted pairs. Spike synchrony wasnot fully blocked by the AMPA receptor antagonist NBQX forany pair combination, and was abolished by NBQX plus NMDAreceptor antagonist dichlorokynurenic acid only in mitral-mitralpairs. Our results suggest that glomerulus-specific spikesynchrony in olfactory bulb principal cells depends primarily ongap junctions, and may be enhanced by mutual excitation viaionotropic glutamate receptors. Glomeruli may split sensoryinformation into parallel data streams conveyed by mitral andtufted cells, encoding different aspects of odor stimuli. Spikesynchronization provides a substrate for temporal binding ofolfactory receptor identity for these parallel streams, even if theyare received and decoded by distinct cortical circuits.94 | AChemS Abstracts 2009

#P217 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisAdult neurogenesis in the mouse accessory olfactory bulbAlexia Nunez-Parra, Ricardo C. AranedaNACS Program & Biology Department, University of MarylandCollege Park, MD, USAThe olfactory bulb is one of the few regions in the brain thatexhibits adult neurogenesis. In adult mice newly born cellsoriginate in the subventricular zone and migrate through therostral migratory stream to the olfactory bulb. These cells matureinto inhibitory neurons, the granule and periglomerular cells, andare functionally integrated into the existing neuronal network.Adult neurogenesis has been extensively characterized in the mainolfactory bulb (MOB) and it has been shown to vary underdifferent physiological conditions (i.e. mating, exposure to theconspecifics odors and odor-enriched environments amongothers). However, little is known about the role and extent ofadult neurogenesis in the accessory olfactory bulb (AOB), aregion of the bulb involved in the processing of pheromonalinformation. Here, we determined the extent of adultneurogenesis in the mice AOB using immunohistochemicaltechniques and BrdU to label newly born cells. We foundabundant labeled cells in the granule cell layer (GCL) of the AOB(4,191±564 and 2,759±573 BrdU + cells/mm 3 , in male and femalemice respectively) with no significant differences betweengenders. The majority of the BrdU + cells corresponded to neurons(93%), as determined by double labeling with NeuN, a marker ofmature neurons. Interestingly, the number of BrdU + cells in theGCL of the AOB was significantly lower compared to thenumber of BrdU + cells in the GCL of the MOB (10,390±105 and9,274 ±1,084 BrdU + cells/mm 3 ; males and females respectively;p

neuron depletion. Adult mice were given 5-bromodeoxyuridine(BrdU) 3 weeks after unilateral bulbar injection of NMDA. Theywere killed 4 days, 2 wks, and 5 wks later. Similar to the effects ofbulbectomy, we found increased numbers of BrdU(+) cells at 4days in the epithelium on the treated side (112 vs 52 cells/mmcontralaterally). Surprisingly, there were also more BrdU (+)survivors on the treated side at 2 wks (32 vs. 24 cells/mm). By 5wks, numbers were similar to control counts, and survivingmature neurons persisted in the deprived epithelium as seen withdouble-labeling for olfactory marker protein. Within theforebrain, bulb damage caused increased proliferation of SVZprogenitors, and these continued to migrate to the bulb in therostral migratory stream (RMS). By 2 wks, most BrdU (+) cells onthe normal side had reached the bulb, while on the lesioned side,most BrdU (+) cells were still contained within the RMS.Increased proliferation was accompanied by an increase in RMSvolume on the treated side (39.9 vs 19.1 mm 3 X 10-3 ), and an increasein TUNEL labeling. Labeling with neuronal markers showed thatnew neurons were added to the damaged bulb. These resultsindicate that some OSNs are capable of long-term survival afterdepletion of targets. Moreover, bulb injury significantly alters theproliferation and migration of SVZ/RMS precursors.#P221 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisGlomerular Regulation of Mitral Cell Responses toSensory InputZuoyi Shao, Adam C. Puche, Michael T. ShipleyDepartment of Anatomy & Neurobiology, Program inNeuroscience, University of Maryland School of MedicineBaltimore, MD, USAOlfactory signals are initially processed in glomeruli, whereolfactory nerve (ON) axons form excitatory synapses ontoprincipal output neurons, mitral/tufted (M/T) cells. M/T cells arethought to be regulated mainly by inhibition at their lateraldendrites from GABAergic granule cells (GC) but less is knownabout inhibition occurring at their glomerular tuft fromGABAergic periglomerular (PG) cells. We examined the relativecontributions of glomerular and infraglomerular inhibition ofmitral cells in bulb slices. ON stimulation produces an initialmonosynaptic EPSC in mitral cells that is interrupted by a shortlatency burst of IPSCs followed by a protracted train ofintermittent IPSCs. Addition of APV, which has been shown toblock the M/T-GC feedback circuit, significantly reduced lateIPSCs suggesting that they derive from GCs, but had little effecton the early IPSC barrage. In contrast, microinjection of gabazine(GBZ) into glomeruli blocked the early burst of IPSCs but hadlittle effect on the late IPSCs. How does this affect mitral celloutput? Mitral cells respond to ON input with a long lastingdepolarization (LLD) upon which rides an initial short latencyspike burst followed by sparse later spikes. Removal of M/T-GCinhibition with APV had little effect on M/T spike responses toON stimulation. However, microinjection of GBZ to blockglomerular inhibition increased M/T spike output ~30-fold.Glomerular inhibition also dramatically regulated the magnitudeand duration of mitral cell LLDs. These data suggest glomerularinhibition is a much more potent regulator of mitral cell responsesto sensory input that previously considered.#P222 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisCharacteristics of spontaneous and evoked EPSCs ofinterneurons in the superficial external plexiform layerof olfactory bulbYu-Feng Wang, Kathryn A HamiltonLSU Health Sciences Center- Shreveport Shreveport, LA, USAInterneurons in several olfactory bulb layers are excited bymitral/tufted cells and provide feedback/lateral inhibition thatshapes M/T cell spontaneous spiking/bursting and responses toolfactory input. At some M/T cell-interneuron synapses, AMPAreceptors mediate fast interneuron excitation that results in fastM/T cell inhibition. At other synapses, NMDA receptors mediateslower interneuron excitation that results in slower, prolongedM/T cell inhibition. Here, we characterized spontaneous EPSCsof interneurons in the superficial EPL of mouse olfactory bulbslices and responses of cells in this region to glomerular-layerstimulation. Most superficial interneurons (26/27) spontaneouslygenerated EPSC clusters. EPSC frequency within clusters (112.2 ±9.4.0 Hz) was significantly higher than before clusters (37.5 ± 3.8Hz, P

educed granule cell spiking. These results indicate that a1 anda2 receptor activation exert opposing effects on granule cellexcitability. a1 and a2 receptor subtypes have differing affinitiesfor NE. Consequently, granule cell-mediated inhibition may bebi-directionally modulated as a function of extracellular NElevels, which in turn, is dependent on behavioral state-dependentvariations in locus coeruleus neuronal firing rates.#P224 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisTaurine deficiency causes loss of mitral cells in theolfactory bulb of miceMartin Witt 1 , Maria Kammerer 2 , Ulrich Warskulat 3 ,Dieter Häussinger 3 , Thomas Hummel 41University of Rostock, Dept. of Anatomy Rostock, Germany,2TU Dresden, Dept. of Anatomy Dresden, Germany, 3 Universityof Düsseldorf, Experimental Hepatology Düsseldorf, Germany,4TU Dresden, Dept. of Otorhinolaryngology Dresden, GermanyAim: Taurine is, after glutamate, the most abundant free aminoacid in the cerebral cortex and in the olfactory bulb (OB). Taurinewas found to play an important role in regulating thedepolarization-evoked GABA release via GABA receptors.Furthermore, taurine is involved in cell volume homeostasis,antioxidant defense and protein stabilization. Previous studies ontaurine transporter knockout mice (taut -/-) showed degenerationof retina, skeletal muscle and olfactory epithelium. The aim of thisstudy was to investigate cellular reactions due to taurinedeficiency of more central olfactory components, such as mitralcells, which constitute the major output neurons of the OB.Methods: The present study assesses quantitative differencesbetween taut -/- mice and controls (on postnatal day 21, 42, 70)concerning the size of the OB as well as numbers andcircumference of glomeruli and mitral cells. For histochemicalidentification of mitral cells in tissue sections we used an antibodyagainst PGP 9.5. Results and Conclusions: Taut -/- mice hadsignificantly smaller OBs than controls. Furthermore, the averagecell circumference of mitral cells is higher in control mice of everyage. After 21d, taut-/- animals showed more mitral cells, but laterthey presented significantly less mitral cells than controls. Also,the OB size of taut -/- mice were significantly smaller in taut -/-mice. The results suggest that taurine plays an important role indevelopment and maintenance of neurons in the olfactorypathway, especially during embryogenesis. Further, loss ofolfactory receptor neurons may lead to a subsequent loss of thesecondary relay neurons, namely mitral cells.#P225 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisAdult and developmental expression of a GABA transporter bya subset of centrally derived glial cells in the antennal lobe ofthe mothLynne A Oland, Nicholas J Gibson, Leslie P TolbertUniversity of Arizona Tucson, AZ, USAA subset of glial cells in the olfactory (antennal) lobe (AL) of themoth expresses a high-affinity membrane GABA transporter(MsGAT) throughout their extent. Early in development of theAL, GABAergic dendrites extend into the shell of glial cells thatsurrounds the neuropil and that includes the MsGAT-positivecells. In the adult, GABAergic dendrites form a dense meshworkof processes within the glia-surrounded glomerular neuropil. Thejuxtaposition of GABAergic dendrites and transporter-expressingglia suggests that the transporter may be important in modulatingthe GABA levels to which neurons and glia cells are exposed inboth developing and adult systems. Using immunocytochemistry,we have shown that the transporter is expressed from thebeginning of metamorphic development in certain glia but not indeveloping neurons. We also have shown that (1) MsGATcontinues to be expressed in the adult, in a subset of glia that havethe morphological appearance of a cell type we have called“complex” glia, (2) MsGAT is not found in adult AL neurons, and(3) GABA is not detectable in MsGAT-positive glial cells underresting conditions. GABA is, however, detectable in most glialcells after brief incubation in 10-50 uM GABA; the intensity ofGABA labeling in the dendrites of GABAergic neurons is greatlyenhanced under the same conditions. These data suggest that thekinetics of transporter-mediated GABA uptake into glial cellsmay be relatively slow or that the transporter has a nontransporterfunction in vivo despite its similarity to rat and humanGAT-1 in sequence and in biochemical and pharmacologicalprofile when expressed in Xenopus oocytes (Mbungu et al.,1995). The data also suggest that a second, as yet unidentified,form of GABA transporter may be present on Manduca neurons.#P226 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisHeterogeneous Expression of Pannexin 1 and Pannexin 2in the Olfactory Epithelium and Olfactory BulbHonghong Zhang, Chunbo ZhangDepartment of Biological, Chemical and Physical Sciences,Illinois Institute of Technology Chicago, IL, USAGap junctions regulate a variety of functions by directlyconnecting two cells through intercellular channels. Gap junctionsare formed by connexins or pannexin gene families. Connexinsand Pannexins may form independent gap junction channels inthe same tissues. Here, we report expression patterns of pannexin1 (Px1) and pannexin 2 (Px2) in the olfactory system of adultmice. In situ hybridization revealed that mRNAs for Px1 and Px2were expressed in the olfactory epithelium and olfactory bulb.Cells expressing Px1 and Px2 were distributed in themain olfactory bulb and the accessory olfactory bulb. Althoughexpressed in spatial patterns, many mitral cells, tufted cells,periglomerular cells and granule cells were Px1 and Px2 positive.Expression of Px1 was weak in portions of the dorsal-lateralolfactory bulb, while the medial regions had relatively highexpression. In contrast, expression of Px2 was stronger in thedorsal and lateral regions than medial regions of the olfactorybulb. There were more Px2 mRNA positive mitral cells andgranule cells compared to those of Px1. Expression of Px1 andPx2 was mainly found in cell bodies below the supporting celllayer in the olfactory epithelium although there might be Px2positive supporting cells in few areas. A majority of the olfactoryepithelium expressed Px1 and Px2 while degrees of expressionvaried among neighboring cells. In summary, Px1 and Px2 arespatially expressed in neurons in the olfactory epithelium andolfactory bulb. Our findings of expression of pannexins in theolfactory system of adult mice raise the novel possibility thatpannexins play a role in information processing in the olfactorysensation. Demonstration of expression patterns of Px1 and Px2in the olfactory system provides anatomical basis for futurefunctional studies.P O S T E R SAbstracts | 97

#P227 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisChloride imaging in trigeminal sensory neurons of miceDebbie Radtke 1,2 , Nicole Schoebel 1,2,3,4 , Hanns Hatt 1,2,4 ,Jennifer Spehr 11Department of Cellular Physiology, Ruhr-University Bochum,Germany, 2 Ruhr-University Research School Bochum,Germany, 3 Graduiertenkolleg “Development and Plasticityof the Nervous System”, Ruhr-University Bochum, Germany,4International Graduate School of Neuroscience,Ruhr-University Bochum, GermanyThe trigeminal system has a warning function that protects thebody from potential noxious stimuli. Receptors located on freetrigeminal nerve endings detect different environmental stimulilike temperature, touch and chemicals. Recent work showed theinvolvement of ligand-gated cation channels in the detection ofchemical stimuli. Until now, a potential role of ligand-gatedchloride channels in trigeminal chemodetection has not beeninvestigated. In contrast to central neurons, in which theexpression of chloride transporters is changed postnatally,trigeminal ganglion (TG) neurons keep high levels of theNa + K + 2Cl - cotransporter NKCC1 and thereby probablyaccumulate chloride intracellularly. Thus, opening of a chlorideconductance would lead to a chloride efflux and therebydepolarizing the neuron. Indeed, current work in our lab showsCa 2+ transients upon stimulation with g-aminobutyric acid(GABA) in TG neurons of mice in Ca 2+ imaging experiments.Here, we use the chloride imaging technique to investigatechanges of intracellular chloride concentration upon GABAapplication on dissociated TG neurons. We show that GABAstimulation leads to a chloride efflux in soma and neurites.Creation of a higher Cl - gradient across the cell membrane byremoval of extracellular Cl - enhances the GABA-induced Cl -efflux. In further experiments we will characterize this Cl - effluxusing pharmacological tools. Our data show that opening of achloride conductance by GABA leads to an efflux of Cl - and thusto a depolarization of trigeminal sensory neurons. Neuronalexcitation by activation of GABA receptors makes them potentialtargets for the trigeminal perception of toxic chemicals.#P228 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisOdor discrimination by mice with long-term unilateral narisocclusion and contralateral bulbectomyCathy Angely, David M. CoppolaRandolph-Macon College Ashland, VA, USAUnilateral naris occlusion (UNO) has been the most commonmethod of effecting stimulus deprivation in studies of olfactoryplasticity. However, despite the large corpus on this manipulation,dating back to the 19 th century, there is almost nothing knownabout the behavioral capabilities of animals raised with UNO.Here we report the results of olfactory habituation studies on twogroups (n = 38) of control and perinatally UNO adult mice beforeand after unilateral bulbectomy (bulb-x). Control and UNOmice formed two groups termed young (1-3 months) and old(>6 months). For UNO mice, the bulb-x was opposite the side ofocclusion. Olfactory discrimination was tested using a two-odorhabituation paradigm in which investigation times to sixconsecutive presentation of one odor were compared to that for anovel odor presented in a seventh trial. The odors were 0.1% v/vethyl butyrate or isoamyl acetate in mineral oil or mixtures ofthese two solutions. If mice showed habituation-dishabituation tothe pure odors they were tested with decreasing dilutions of testodor mixed in the habituation odor (1:10, 1:50, 1:250). Foruntreated mice neither age nor bulb-x significantly influenced theability to discriminate between the habituating odor and the testodor down to a dilution mixture of 1:50. Also, discrimination wasunaffected by UNO prior to bulb-x. Surprisingly, after bulb-x,young and old UNO mice were still able to discriminate thehabituation and test odor down to a mixture of 1:50. Youngbulb-x mice in the control and UNO group failed to discriminatethe habituation and test odor at a dilution of 1:250. Thesecounterintuitive results suggest that UNO is neither an absolutemethod of deprivation nor does its diminish odor discrimination.#P229 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisCharacterization of GABA-Induced Responses ofTrigeminal Sensory NeuronsNicole Schoebel 1,2,3,4 , Annika Cichy 1 , Debbie Radtke 1,4 ,Hanns Hatt 1,3,4 , Jennifer Spehr 11Department of Cellular Physiology, Ruhr-University Bochum,Germany, 2 Graduiertenkolleg Bochum, Germany, 3 InternationalGraduate School of Neuroscience, Ruhr-University Bochum,Germany, 4 Ruhr-University Research School Bochum, GermanyIn the adult central nervous system opening of chlorideconductances leads to neuronal inhibition. Different from centralneurons, some populations of peripheral neurons namelyolfactory receptor neurons (OSNs) and neurons of the dorsal rootganglia (DRG) maintain high levels of the Na + K + 2Cl - -cotransporter (NKCC1) at adulthood. NKCC1 accumulateschloride in OSNs and DRG neurons which results in cellulardepolarization upon opening of chloride channels. As aconsequence, DRG neurons are excited by the inhibitoryneurotransmitter g-aminobutyric acid (GABA). Althoughproposed, there is no experimental evidence showing that thesame logic applies to neurons of the trigeminal ganglia (TG) todate. Here, we examine the effect of GABA on primary sensoryneurons isolated from murine trigeminal ganglia. In whole-cellpatch-clamp experiments GABA elicited responses in all TGNs ina dose dependent manner. Furthermore, GABA stimulation leadto a quick and robust increase of intracellular calcium in TGneurons observable in calcium-imaging measurements. GABAinducedexcitation could be seen in neurons of differentdevelopmental stages and was independent of culturingconditions. Preincubation with the NKCC1 blocker bumetanideinhibited the calcium rise in TG neurons from early postnatal aswell as adult animals suggesting that a high intracellular Cl -concentration is essential for the response. Pharmacologicalcharacterizations showed that the responses are mediated byGABA A receptors and involve an influx of extracellular calciumvia voltage gated calcium channels (VGCCs). In summary, wesuggest intracellular Cl - accumulation in TG neurons produced byNKCC1 leading to a depolarizing efflux of chloride uponGABA A receptor opening which in turn is followed by an influxof extracellular Ca 2+ through VGCCs.98 | AChemS Abstracts 2009

#P230 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisProperties of rostral nucleus of the solitary tract (rNST)GABAergic interneuronsMin Wang 1 , Robert M. Bradley 1,21Department of Biologic and Material Sciences, School ofDentistry, University of Michigan Ann Arbor, MI, USA,2Department of Molecular and Integrative Physiology,MedicalSchool,University of Michigan Ann Arbor, MI, USAInhibition has been shown to play a significant role in rNSTsensory processing mediated by GABAergic interneurons.However, the properties of these inhibitory interneurons have notbeen systematically investigated. We have used transgenic mice inwhich enhanced green fluorescent protein (EGFP) expression islinked to glutamic acid decarboxylase expression (GAD + ) toidentify and characterize the rNST GABAergic interneurons. Incoronal brainstem sections GABAergic interneurons werelocalized to the ventral subdivision of rNST. The GAD-EGFPneurons also immunoreact with GABA and NeuN antibodies anddifferent subpopulations of these neurons also immunostain withsomastatin and parvalbumin. In whole cell brain slice recordingsGAD-EGFP neurons could be grouped based on their firing andmorphologic properties. In response to a depolarizing currentpulse 71% of the GAD-EGFP neurons responded with a shortinitial burst of action potentials, 13% responded with a stutterfiring pattern and 16% responded with a tonic firing pattern.The burst firing neurons had a small round soma area. Stutterfiring neurons had larger soma areas and round cell bodies andtonic firing neurons had large fusiform or multipolar somas.In conclusion, the rNST GAD-EGFP interneurons differ inpeptide expression and have heterogeneous physiological andmorphological properties. These differences may indicate thatthese inhibitory interneurons may have different roles in rNSTsensory processing of information derived from taste receptorsin the oral cavity.#P231 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisSox2 Regulation of Neurogenesis in the Adult OlfactoryEpitheliumAdam I Packard, James E SchwobTufts University School of Medicine Boston, MA, USASox2 is expressed in multiple cell types in the adult olfactoryepithelium (OE), including horizontal basal cells, globose basalcells and sustentacular cells. During lesion-induced regenerationof the OE, residual activated stem and progenitor cells expressSox2 robustly. The absence of Sox2 from neurons suggests that itmay function to suppress neuronal differentiation in both thenormal and regenerative settings. To test this we used areplication-incompetent retrovirus to drive expression of Sox2-IRES-eGFP in the regenerating mouse OE. The composition ofthe clones derived from the infected progenitors was characterizedusing cell type-specific antibodies. Sox2-infected clones have agreater number of cells on average compared with the controlvector (eGFP-only). Surprisingly, Sox2-infected clones didcontain numerous neurons as shown by co-expression of GFPwith Tuj1 and/or PGP9.5. Thus, Sox2 seems to be incapable ofblocking the differentiation of olfactory neurons on its own.However, immunoreactive Sox2 cannot be detected in aconsiderable percentage of GFP-labeled neurons, despiteenhanced levels of Sox2 expression by infected sustentacular andbasal cells. Moreover, those neurons in which Sox2 expression isdetectible by immunostaining were more lightly labeled thanother infected cells. This constellation of findings suggests thatSox2 is being degraded in neurons infected with the Sox2 vector.Of note, no clone-derived, Sox2-expressing neurons co-expressPax6, a known binding partner, indicating that Sox2 may need aco-factor to suppress neuronal differentiation in the OE. Insummary, selective over-expression of Sox2 is not able to suppressolfactory neuronal differentiation by itself, which may reflect aneed to partner with Pax6, as in other tissues, to accomplish anyinhibition.#P232 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisPACAP Enhances Cell Survival in Cultured Slices ofMouse Olfactory BulbMary T Lucero, Shami KanekarUniversity of Utah, Department of Physiology, NeuroscienceProgram Salt Lake City, UT, USAOur lab has previously demonstrated the importance of theneuropeptide PACAP in protection of neurons of the olfactoryepithelium against both axotomy-induced and cytokine-inducedapoptosis. Expression of PACAP and its receptor PAC1 iswidespread in the olfactory bulb (OB). In this study, we thereforeexamined whether PACAP enhances cell survival in the OB.We cut 300 micron thick live slices of the OB on a vibratome.Slices were immediately transferred into tissue culture media(DMEM/F12, 0.5% BSA) containing PACAP at 4 nM or 40 nM,or vehicle alone. Slices were cultured in a tissue culture incubatorat 37 o C for 21 hours, and then treated with 0.5% propidiumiodide to label dying cells. Slices were then fixed and all cellslabeled with sytox-green. Slices were imaged on a Zeiss LSM500confocal microscope, PI-labeled cells and total cells were counted,and the percent of dying /total cells calculated. After 21 hrs inculture, the percentage of dying cells in the 4 nM PACAP groupwas similar to control: 90 ± 4% that of control. The 40 nMPACAP group however showed significantly lower percentagesof dying cells than both control and 4 nM PACAP (One WayANOVA, p

#P233 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisCytoarchitecture of Neuroblasts and their Stem Cell NicheMaintaining Adult Neurogenesis in the Olfactory Midbrainof Spiny Lobsters, Panulirus argusManfred Schmidt, Charles D. DerbyNeuroscience Institute, Georgia State University Atlanta,GA, USAAdult neurogenesis persists in the olfactory midbrain of spinylobsters, Panulirus argus. Neuronal precursor cells are located in asmall proliferation zone (PZ) in each of the four soma clusters oflocal and projection neurons. One neuronal stem cell – a largeadult neuroblast (aNB) - is located close to each PZ and is itselfassociated with a unique clump of cells constituting a putativestem cell niche (Schmidt, J. Comp. Neurol. 503:64-84, 2007). Weanalyzed the cytoarchitecture of the aNB and the clump of cellswith immunocytochemistry and TEM. These analyses showedthat the clump is comprised of cells (clump cells) whose smallsomata form a dense mantle around a nucleus-free core and thatthe aNB has a unique hourglass-like shape. The peripheral part ofthe aNB contains a large nucleus and is connected via a thincytoplasmic bridge to a bulb-shaped ‘foot’ extending into core ofthe clump of cells. The clump cells are bipolar with a longoutward-facing process and a shorter process reaching into thecore of the clump. The outward-facing processes form a strandthat surrounds the peripheral part of the aNB and projects furtherto the PZ. The shorter processes are convoluted and completelycover the bulbous foot of the aNB. Processes of multipolar, somaassociatedglial cells envelope clump and strand in several layersand separate them from neighboring neuronal somata andarterioles. We conclude that the clump of cells has morphologicalfeatures of a protected stem cell niche, in which clump cellsconstitute the microenvironment of the aNB and insulate it fromthe surrounding tissue. Since the clump cells differ from glial cellsin immunocytochemical properties and in overt morphology, wehypothesize that they maintain embryonic characters, a commonfeature of stem cell niches in adult tissues.to be effective in wildtype and transgenic mice as well as rats.Given its versatility, robustness, and both time and costeffectiveness, this method offers a powerful new way to usegenetic manipulation to understand adult neurogenesis.#P235 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisDeafferentation affects cell genesis and neuron survivalin the olfactory bulb of adult zebrafishChristine A. Byrd-Jacobs, Ruth VillanuevaWestern Michigan University Kalamazoo, MI, USAThe potential effects of afferent innervation on adult neurogenesisin the olfactory bulb were examined with deafferentation.Olfactory organs of adult zebrafish were completely ablated bycautery to cause permanent denervation of the olfactory bulb.Animals were exposed to bromodeoxyuridine then examinedusing immunocytochemistry following short (4 hour) or long(3 week) survival periods. Short survival times allowed analysisof cell proliferation in the bulb and long survival times permittedinvestigation of survival of adult-formed cells. When examinedimmediately after deafferentation, no effect on cell proliferationwas observed. However, there was an effect on the number ofadult-formed cells present in the bulb three weeks later suggestingthat afferent removal influenced the fate of newly formed cells byimpacting subsequent divisions, maturation, or survival of thosecells. One week of deafferentation altered the pattern of cellgenesis, with a significant increase in the number of dividing cellslocated in the olfactory bulb. Survival also was impacted by oneweek of deafferentation since there was an elevation in thenumber of adult-formed cells in the glomerular layer of the bulb.Sham surgery and longer deafferentation times did not impacteither proliferation or survival of adult-formed cells. Thus,afferent innervation is necessary for normal cell proliferation andmaintenance of the olfactory bulb in adult zebrafish. Themechanisms by which olfactory axons exert an influence on theprocess of adult neurogenesis will be the subject of future studies.#P234 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisEctopic gene expression by postnatal electroporationduring olfactory interneurons neurogenesisDongjing Zou 1 , Alex Chesler 1 , Claire Le Pichon 1 , Jesse Brann 1 ,Ricardo Araneda 2 , Stuart Firestein 11Department of Biological Sciences, Columbia University NewYork, NY, USA, 2 Department of Biology, University of MarylandCollege Park, MD, USANeurogenesis persists in the olfactory system throughout life.The mechanisms of how new neurons are generated, how theyintegrate into circuits, and their role in coding remain mysteries.Here we report a technique that will greatly facilitate research intothese questions. We found that electroporation can be used torobustly and selectively label progenitors in the SubventicularZone. The approach was performed postnatally, without surgery,and with near 100% success rates. Labeling was found in allclasses of interneurons in the olfactory bulb, persisted toadulthood and had no adverse effects. The broad utility ofelectroporation was demonstrated by encoding a calcium sensorand markers of intracellular organelles. The approach was found#P236 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisCell specific deletion of BDNF leads to impairments inmurine adult olfactory neurogenesisKevin G Bath, Christine Neeb, Deqiang Jing, Francis S LeeWeill Medical College of Cornell New York, NY, USANeurotrophins are a class of molecules known to influence thedevelopment and survival of cells of the nervous system. BDNFsignaling through TrkB receptors is important for postnatalmodifications of the nervous system such as synaptic remodeling,dendritic outgrowth, and cell survival. In adult animals, theapplication or overexpression of exogenous BDNF has beenshown to impact neurogenesis. We have recently shown, throughthe use of several genetically engineered lines of mice and novelreagents that endogenously produced BDNF plays a significantrole in regulating adult olfactory bulb (OB) neurogenesis.Furthermore, we have shown that adult OB neurogenesis reliesheavily upon the regulated release of BDNF and signalingthrough TrkB and not p75 receptors. However, the source of theendogenously released BDNF has remained elusive. We present100 | AChemS Abstracts 2009

data here from mouse studies using Cre/LoxP site-specificrecombination in which we genetically remove BDNF fromdiscrete populations of cells. To our knowledge, these studies arethe first to attempt to localize the source of BDNF controllingadult neurogenesis.#P237 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisIn vivo optical imaging of experience-induced olfactory bulbglomerular plasticityMax L. Fletcher 1 , Johannes Richter 2 , Wei R. Chen 11University of Texas Medical School Department of Neurobiologyand Anatomy Houston, TX, USA, 2 Yale University School ofMedicine New Haven, CT, USAWhile the olfactory system has been shown to have a remarkablecapability for undergoing experience-dependent plasticity, howsuch odor memories are imprinted in the adult olfactory neuronalcircuits remains unclear. This process most likely involves changesat multiple stages along the central olfactory processing pathways.One interesting site for plasticity is the olfactory glomerular layer.Within this layer, the organization of receptor neuron inputsallows odorant information to be transformed into an odorantspecificspatial map of glomerular activity. We have visualizedsuch activity patterns in vivo by using a recently-developedtransgenic mouse with a GFP-based calcium indicator(G-CaMP2) expressed in output neurons postsynaptic toolfactory nerve inputs. Unlike previously applied optical imagingmethods, this mouse allowed us to observed purely postsynapticodor maps in the glomerular layer. Using this mouse, we testedthe hypothesis that the olfactory learning process can significantlyalter olfactory bulb postsynaptic glomerular odorantrepresentations for the trained odorant. This was carried out bycomparing the odorant-evoked glomerular activity patterns in thesame animal before and after olfactory associative conditioningwith foot shock. Preliminary data suggests that conditioning witha given odorant significantly alters glomerular responses to thatodorant following training. These results suggest that simpleforms of olfactory experience can have a significant impact onolfactory odor coding even at the earliest stages of centralprocessing.#P238 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisMaternal Modulation of the Functional Emergence of theHippocampus in Context Fear Learning in Infant RatsCharlis Raineki 1,2,3 , Parker Holman 3 , Melissa Bugg 3 , AllysonBeasley 3 , Regina M. Sullivan 1,2,31Emotional Brain Institute, Nathan S. Kline Institute forPsychiatric Research Orangeburg, NY, USA, 2 Child andAdolescent Psychiatry, NYU Langone Medical Center New York,NY, USA, 3 Department of Zoology, University of OklahomaNorman, OK, USAlearning ontogenetically emerges at weaning. First, we assesswhether the hippocampus is responsible for pups’ newly emergingcontext learning. In all experiments, postnatal day (PN) 21 andPN24 rat pups received 10 pairings of odor-0.5mA shock orcontrol unpaired odor-shock or odor only. Some pups were usedfor context, cue or odor avoidance tests, while the remaining pupswere used for c-Fos immunohistochemistry to assess hippocampalactivity during acquisition. Our results show that cue and odoravoidance learning were similar at both ages, while contextual fearlearning and learning associated hippocampal (CA1, CA3 anddentate gyrus) activity only occurred in PN24 paired pups.To assess a causal relationship between the hippocampus andcontext conditioning, we infused muscimol into the hippocampus,which blocked acquisition of context fear learning in PN24 pups,but did not affect cue learning or aversion to the odor at PN21 orPN24. Secondly, we assess whether the emergence of the contextfear learning is modulated by the maternal presence. PN24 ratpups were odor-shock conditioned with or without maternalpresence. Similarly to muscimol infusion into the hippocampusresult, maternal presence prevents context fear learning at PN24but do not affect cue learning and odor aversion. The resultssuggest that maternal presence modulates the newly emergingcontextual fear learning exhibited by PN24 pups that is supportedby the hippocampus.#P239 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisRethinking statistical analysis of associative learning in anolfactometerNicolas Busquet, Diego RestrepoUniversity of Colorado Denver Denver, CO, USAStatistical analyses of performance in olfactory learning taskstypically focus on confirming that the association has beenlearned rather than investigating the process through which it isestablished. In the former approach, the animal needs to beproficient in the task before a particular association can bedemonstrated. Because the animal may make the association andthus treat the stimuli differently before reaching the performancestandard, the statistical analysis of the acquisition process shouldnot be constrained by a set criterion. Here I present a new methodto calculate when the subject’s behavior departs from randomness.This is done by comparing the probability value associated withthe animal’s performance with a spectrum of probability valuesgenerated from multiple simulations of random behavior in thesame task. These probability values are incremented on a singleeventbasis to detect more precise timing of the learning process.This new approach is also more flexible in handling variabilitywithin and across individuals and sessions. The efficacy of thismethod is evident in the reported results from a pilot study usingnatural and artificial odors. Applying our method providesevidence that mice can achieve better than chance performanceconsiderably sooner than previously demonstrated with thestandard statistical analysis.P O S T E R SThe hippocampus is important for the formation of associativememories, such as acquiring information about context (i.e. theplace where an experience occurred) during emotional learning(i.e. fear conditioning). Previous work suggests that contextAbstracts | 101

#P240 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisChanges in Sniffing Patterns During Learning of theAssociation of Odor with RewardVanessa Carmean 1 , Jennifer D Whitesell 1,2 , Diego Restrepo 1,21Neuroscience Program, University of Colorado Denver AnschutzMedical Campus Aurora, CO, USA, 2 Department of Cell andDevelopmental Biology, University of Colorado Denver AnschutzMedical Campus Aurora, CO, USAActive sniffing has been hypothesized to provide a filter for inputto the olfactory system, and firing of mitral cells in the olfactorybulb has been demonstrated to be coupled with respiration. Ourgoal was to investigate changes in sniffing as mice learn toassociate a novel odor with reward. Mice were implanted with anasal cannula that allowed measurements of changes in intranasalpressure and they were exposed to novel odors in a go-no go task.Odors were associated with either a water reward deliveredthrough a tube or no reward, and the mouse responded to theodor stimuli by licking on a tube for the rewarded odor or notlicking for the unrewarded odor. Sniff frequency and amplitude ofintranasal pressure changes were recorded, along with lickbehavior. Our preliminary data indicates that variability insniffing frequency and amplitude decreases as the mouse learnsthe association during the go-no go session. The data also revealsthat sniffing frequency increases in anticipation of odors, andamplitude changes as odor associations are learned.#P241 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisLong-term reductions of olfactory sensitivity due toshort-term exposures to a peri-threshold odorantJennifer Chen 1 , Wen Zhou 1 , Meng Zhang 2 , Denise Chen 11Rice University Houston, TX, USA, 2 Harbin Medical UniversityHarbin, ChinaAdaptation refers to reduced sensitivity to a stimulus due toexposure to the stimulus. It is standard to classify olfactoryadaptation as short-term versus long-term, with the assumptionthat rapid exposures (seconds to minutes) lead to quick recoveriesfrom the odorant (within minutes) while prolonged exposures(hours to days and weeks) yield slow recoveries (weeks or longer).In the current study, we assessed the olfactory threshold ofphenylethyl alcohol (PEA) of 5 female subjects once every threedays over a course of two months. Each time, the subjects wereexposed to peri-threshold concentrations of PEA for 2s perminute for a total of under 40s of PEA exposure time. We showeda significant monotonic reduction of PEA sensitivity in the courseof testing in all 5 subjects and large individual variations in theseverity of the reduction. Our findings suggest that mere shorttermexposures to a peri-threshold odorant can amount toprogressive long-term adaptation, and provide new insights in theinterplay between the receptor and higher cognitive levels ofolfactory adaptation.#P242 Poster session V: Chemosensory memory/Central synaptic physiology/NeurogenesisLearned preferences for odours determined by individualvariations in taste intensity and hedonicsJohn Prescott 1 , Martin Yeomans 2 , Natalie Gould 21The University of Newcastle Ourimbah, Australia, 2 University ofSussex Brighton, United KingdomRepeated co-exposure of novel odors with sweet or bitter tasteschanges their hedonic and sensory characteristics. However,individual variations in responses to tastes could influence theseconditioned effects. Thus, tasters (T) of 6-n-propylthiouracil(PROP) find saccharin (Sacc) both more bitter and more sweetthan do PROP non-tasters (NTs). We therefore predicted thatacquired liking for odors conditioned by pairing with Sacc wouldvary with PROP taster status. Since odor perceptualcharacteristics, e.g., smelled sweetness and bitterness, arise viaassociation with tastes, we tested if PROP taster status wouldinfluence such learned effects. We also examined the impact ofindividual variations in hedonic responses to sweet tastes (thesweet liker/disliker dichotomy). Eighty-seven volunteersevaluated two novel odors before and after co-exposure of oneodor with 0.0004M Sacc and one with water. PROP taster statuswas based on ratings of 3.2mM PROP, and sweet-liker status fromhedonic ratings of sucrose and Sacc solutions. Liking for the Saccpairedodor increased in sweet likers but decreased in sweetdislikers.Both odors were less pleasant post-exposure in thePROP T but not NT groups. The Sacc-paired odor was sweetersmelling post-exposure, regardless of PROP taster or sweet-likerstatus. PROP super-tasters rated the Sacc-paired odor as morebitter smelling post-exposure, in-line with their higher ratings ofSacc bitterness. These data show that acquired liking for, andsensory characteristics of, odors (and hence flavors) is at leastpartly determined by individual differences in perceptual andhedonic responses to bitter and sweet stimuli. Moreover, at leastsome of the PROP group differences in food preferences areprobably due to differential learning processes.#P243 Poster session VI: Chemosensory developmentand Psychophysics ISonic hedgehog and Sox2 expression in taste cell progenitorsin genetic mouse models of gustatory nerve transectionAkira Ito, Michelle M. Sims, Jong-Gwan Kim, Christopher A.NosratDepartment of Restorative Dentistry and Center for CancerResearch, University of Tennessee Health Science CenterMemphis, TN, USAOur previous studies, using double neurotrophin knock out(double-KO) mice in combination (BDNF –/– xNT4 –/– or BDNF –/–xNT3 –/– ), showed severe deficits in the gustatory innervation oftaste buds. The number of taste buds increased in double-KO andwild type (WT) mice during the early stages of taste buddevelopment, as indicated by Troma-1 positive cells. There are nonerve fibers in the proximity of the taste bud progenitors at earlystages of development. Interestingly, after nerve connection stagein taste bud development, fungiform taste bud number decreasedsignificantly in the double-KO compared to WT. While tasteplacode/taste bud induction and initial stages of taste buddevelopment are nerve independent, full maturation and functionare not. To further study the role of early pioneering nerve fibers102 | AChemS Abstracts 2009

in taste bud induction and development, we utilized our double-KO genetic nerve transection mouse models in combination withimmunohistochemistry for two early taste placode/taste budmarkers; Sonic hedgehog (Shh) and Sox2. Embryonic andneonatal double-KO and WT tongues were dissected, fixed andprocessed for immunohistochemistry. Shh positive placodes wereobserved in the lingual epithelium of both double-KO andWT prior to innervation. Shh positive placodes had a similarmorphological appearance in all mice. Sox2 positive cells werealso observed in all mice from E13.5 to P0. Null mutation ofneurotrophins and the subsequent influence on the innervationdid not affect early expression of Shh and Sox2, forwarding ourhypothesis that the initial stages of taste bud development areindependent from innervation.#P244 Poster session VI: Chemosensory developmentand Psychophysics IExpression of Stem Cell Factor and Kit receptor duringdevelopment of the main and accessory olfactory systemsThomas K. Knott, Timothy R. Henion, Gary A. SchwartingUniversity of Massachusetts Medical School Worcester, MA, USAStem Cell Factor (SCF; also known as steel factor or Kit ligand) isa growth factor that signals through the Kit receptor, a type IIIreceptor tyrosine kinase family member. Upon binding by itsligand, Kit receptor dimerizes and autophosphorylates to activatedownstream signaling pathways. Kit signaling is important inseveral processes during nervous system development, includingmigration of neural crest cells. Kit+ cells are expressed in thedorsomedial neural tube and migrate exclusively into the dermiswhere they express markers of the melanocyte lineage. RecentlySCF was identified as a guidance cue for commissural axons.It is required to stimulate the outgrowth of axons that enablesmidline crossing in the developing spinal cord. We have begun toinvestigate the expression of SCF and Kit in the developingolfactory system of mice using immunocytochemical and in situhybridization techniques. Kit is expressed in neurons in thedeveloping olfactory epithelium (OE) and in the vomeronasalorgan (VNO) as early as embryonic day 11 (E11). In contrast,SCF is expressed in the rostral forebrain of early embryonic micebut is largely absent from developing olfactory and vomeronasalneurons. As the olfactory bulb (OB) emerges from the rostraltelencephalon at E12-13, SCF expression is heavily expressed inhe ventral OB adjacent to the cribriform plate where axons fromthe OE and VNO converge following their extension through thenasal mesenchyme. It is also where migrating GnRH neurons exitthe nasal mesenchyme in transit towards the basal forebrain.Studies in mutant mice should allow us to decipher the role ofSCF and Kit in cell migration and axon guidance in theembryonic mouse olfactory system.#P245 Poster session VI: Chemosensory developmentand Psychophysics IDifferentiation and migration of neurons derived from theolfactory placodeAlexandra M. Miller 1,3 , Helen B. Treloar 1 , Charles A. Greer 1,2,31Department of Neurosurgery, Yale University School of MedicineNew Haven, CT, USA, 2 Department of Neurobiology, YaleUniversity School of Medicine New Haven, CT, USA,3Interdepartmental Neuroscience Program (INP) New Haven,CT, USAThe mechanisms that influence the differentiation of olfactorysensory neurons (OSNs) during development are not fullyunderstood. OSNs appear in the olfactory placode (OP) prior toembryonic day 10 (E10) and the first axons penetrate thetelencephalic vesicle at E11 (Hinds, 1971). In addition, apopulation of GnRH+ cells, migrate along the nerve from theOP beginning at ~E11.5 (Wray, 1989). We noticed, beginningaround E9.5, a population of cells emerged from the OP, intothe mesenchyme, between the OP and cerebral vesicle. Tocharacterize these cells, which we have tentatively termedMigrating Olfactory Placode Cells (MOPCs) we used a panel ofneuronal and developmental markers from E9.5 through E13.The data reported here establish the neuronal identity of theMOPCs, their migration from the OP and the spatio-temporalframework of their appearance. Of interest, the MOPCs create apathway between the developing olfactory epithelium and thebulb in the precise location where the olfactory nerve developsbeginning around E11. Thus, this raises the possibility that theMOPCs may create a “scaffold” along which the axons can travelas they move toward the bulb. The data suggest strongly thatthese are the first cells to exit the placode and may be distinctfrom others previously associated with the concurrent migrationof OSN axons, such as the GnRH cells and ensheathing glia thatoccur at a later time (de Carlos, 1995). Of interest, cells within themesenchyme have recently been described which express odorreceptors and may be involved in the targeting of OSN axons(Conzelmann, 2002). It appears the OR-expressing cells and theMOPCs likely represent two distinct neuronal populationsemerging from the placode because of their morphologicalappearance and differences in their temporal framework.#P246 Poster session VI: Chemosensory developmentand Psychophysics IEarly GABAergic Specification of Subventricular DerivedProgenitorsCeline Plachez, Adam C. PucheDepartment of Anatomy and Neurobiology, University ofMaryland, School of Medicine Baltimore, MD, USAP O S T E R SOlfactory bulb interneurons are continuously generatedthroughout development and in adulthood. These neurons areborn in the subventricular zone (SVZ) and migrate along therostral migratory stream (RMS) into the olfactory bulb (OB)where the majority become local GABAergic interneurons.To investigate the differentiation of these GABAergicinterneurons we examined migration in a transgenic mouse whichexpresses green fluorescent protein (GFP) under the control ofthe glutamic acid decarboxylase 67 kDa (GAD67) promoter.During development, and in adult, GFP was expressed by asubpopulation of migratory cells along the rostral migratoryAbstracts | 103

stream and in the olfactory bulb. Doublecortin (DCX) andPolysialic acid neural cell adhesion molecule (PSA-NCAM), bothmarkers of migrating neuroblasts, were found co-expressed by themajority of the GAD67-GFP-positive SVZ-derived progenitorcells. This observation is similar to our previous work showingthat SVZ-derived progenitor cells expressed GAD-65 very earlyin the migratory pathway, and in contrast to tyrosinehydroxylase-GFP phenotype which is acquired only when thecells are in the olfactory bulb. Although the GAD65/67 genes areexpressed early in migration, there is minimal protein productionin the cells within the RMS prior to the olfactory bulb. Takentogether, our results suggest that the SVZ-derived neuroblastsduring migration acquire GABAergic identify (GAD65 orGAD67 gene expression) very early in the SVZ-RMS-OBpathway. This suggests that at least some SVZ progenitorsdifferentiate prior to reaching their final location in theolfactory bulb.#P247 Poster session VI: Chemosensory developmentand Psychophysics IThe positional variability of the P2, M72, and MOR23glomeruli in the mouse main olfactory bulb in young andadult animalsErnesto Salcedo, Tuan Tran, Xuan Ly, Kyle Hanson,Eugene Kronberg, Diego RestrepoUniversity of Colorado Denver Aurora, CO, USAThe surface of the main olfactory bulb (MOB) contains atopographical map of olfactory sensory neuron activation knownas an odor map. Odor maps in genetically inbred animals exposedto the same odorant contain both global similarities and regionaldifferences. A major step towards understanding odor coding inthe olfactory bulb is to understand the source of the variation inthese maps. We have developed an accurate and sensitive methodto map the location of glomeruli on the surface of the olfactorybulb to within biological variability. We have incorporated intoour mapping technique a three-dimensional, digital representationof an average adult mouse olfactory bulb (called a standard bulb).This standard bulb allows us to address alignment issues that canresult from individual differences in bulb size or from technicalerrors during the surgical preparation of the bulbs. To test thesenew mapping tools, our lab has generated a new strain oftransgenic mice which coexpress the green fluorescent protein(GFP) with three different odorant receptors. Each of thesetransgenic animals contains on average six different GFP-labeledglomeruli located in distinct locations on the surface of the MOB.Previous investigation has shown that any given glomerulusoccupies a region of statistical probability on the surface of thebulb. We have mapped the number and location of these glomeruliacross different developmental stages in order to determine theextent of their positional variability in reference to each other asthe bulb develops. By mapping these three different glomeruli, wecan estimate the extent by which the positional permutations of agiven glomerulus occurs in reference to other glomerularpositions in a given bulb across several developmental stages.#P248 Poster session VI: Chemosensory developmentand Psychophysics ISensory inputs modulate olfactory receptor expressionpatterns in the mouse olfactory epitheliumHuikai Tian, Minghong MaDepartment of Neuroscience, University of Pennsylvania Schoolof Medicine Philadelphia, PA, USAPostnatal experience plays critical roles in normal development ofthe olfactory system, which undergoes considerable neurogenesisthroughout life. Odor stimulation is an essential element for cellsurvival, dendritic and axonal refinement, and synaptic plasticityof olfactory sensory neurons (OSNs). Each OSN stably expressesone odorant receptor (OR) from a repertoire of ~1300 and allOSNs with the same OR are distributed within one of the fewbroadly-defined zones. However, it is not clear how suchexpression patterns are shaped by the sensory inputs. Here weinvestigated how sensory deprivation modulates OR expressionpatterns by performing unilateral naris closure on newborn mice.After four-week occlusion, we compared the cell densities of 14selected OR genes in the closed and open side using in situhybridization. The cell density was significantly higher in theopen side for two ORs (MOR174-13 and 40-12) in zone 1 (dorsal)and two ORs (K20 and P2) in zone 2-3 (middle), suggesting thatodor stimulation may promote cell survival or regeneration ofthese OSNs. No differences between the closed and open sidewere observed for three other ORs in the dorsal or middle zone.This may reflect activity-independent survival of these neurons orlack of appropriate ligands in the environment. Surprisingly, allseven ORs (MOR0-2, 160-5, 232-2, 235-1, 236-1, 244-3 and 270-1) from zone 4 (ventral) had a significantly higher cell density inthe deprived side than the open side. Whether this is due to betterprotected OSNs on the closed side or increased celldeath/compromised neurogenesis in the ventral portion of theopen side remains to be determined. Our results indicate thatsensory inputs have differential effects on OSNs expressingdifferent ORs.#P249 Poster session VI: Chemosensory developmentand Psychophysics IInfluences of p53 gene in the development of olfactory neuronsHonghong Zhang, Chunbo ZhangDepartment of Biological, Chemical and Physical Sciences,Illinois Institute of Technology Chicago, IL, USAThe p53 tumor suppressor protein plays an essential role inregulating neuronal apoptosis and survival in the developingnervous system. It mediates neural differentiation and maturation.To examine the role of p53 in the olfactory development andneurogenesis, we studied expression of a few maker proteins ofthe olfactory epithelium in p53 knock out mice. Among them,growth associated protein (GAP-43) is a protein uniquelyexpressed in immature olfactory neurons and olfactory markerprotein (OMP) is expressed in mature olfactory neurons.Olfactory G protein (G a/o ) transmits information from cellsurface receptors to intracellular effectors. Western analysis inpostnatal 3 day p53 heterozygous (p53 +/- ) mice showed thatexpression of GAP-43 was 69% (p

trends in expression of GAP-43, OMP and G a/o . Expression wasreduced to 58%, 60%, and 43%, respectively, but was notsignificantly different from WT, probably due to a small samplesize (n = 3 for p53 -/- ). We observed similar results of GAP-43 andOMP (p

Across all odorants and the 2 presentation conditions, as well asacross the odorants for just retronasal and for just the oral-cavityonly(OCO) presentations, there were significant differences in %correct ID, p 65%) but not OCO (≤ 33%), with OCO geraniol ID at 0%.For 4 of the 6 odorants, retronasal median % correct ID werelarger than corresponding OCO median % correct ID. Within thestudied set of odorants, ID of dl-menthol was difficult.CONCLUSIONS: TRPM8 agonists do not share a commonodorant ID and are responded to differently both betweenretronasal versus OCO presentations and for OCO per se.The OCO differences suggest that TRM8 classification is notsufficient to predict trigeminal responses to odorants. Supportfrom the Food Science Summer Scholars Program, the BiologicalSciences Honors Program, and a Susan Lynn Sage Professorship#P254 Poster session VI: Chemosensory developmentand Psychophysics IEph/Ephrin Expression in the Developing and AdultTaste SystemGennadiy Katsevman, Michael Oleksiak, Natalia Hoshino, MWilliam RochlinLoyola University Chicago Chicago, IL, USAWe are profiling the expression of Eph receptors and their Ephrinligands in the taste system of embryonic to adult mouse and rat.Both classes of protein can initiate signaling cascades that underliecontact dependent repulsion or adhesion, thereby influencingaxon pathfinding, target selection, and epithelial cell arrangement.“Forward” signaling refers to signaling within the Eph-bearingcell; “reverse” signaling is for Ephrin-bearing cells. In E11.5 and14.5 mouse, EphrinB1 is detected in mandibular and chordatympani axons that are bordered by EphB2-positive and EphB3-positive cells, respectively. Thus, reverse signaling could constrictthese axons to their paths. In the tongues of embryonic mouse/ratand postnatal rat, however, anti-EphB1,2,3 labels geniculate andtrigeminal axons; and Ephrins B1 and B2 are most concentrated inthe non-gustatory epithelium avoided by these axons (mouseonly). These data are consistent with a role for forward signalingin restricting the exploration of sensory axons in the target.EphA4, EphA7, and EphrinA2 are also present in embryonicmouse geniculate and trigeminal nerves. We have not detectedEph receptors or ephrins in adult mouse/rat sensory nerves, butboth classes are detected in other adult tissues: In mouse,EphrinB1 and B2 staining of non-gustatory epithelium persists,and EphrinB1 is also detected at low levels within taste buds.In rat fungiform papillae, anti-EphA4 labels taste buds and anti-EphA7 appears to label microvasculature. These results areconsistent with a role for Eph/ephrin signaling in axon guidanceand targeting during development and plasticity, and perhapsduring recovery following injury. In vitro functional assays areunderway to determine if Eph/ephrin signaling supports orinhibits sensory axons throughout development.#P255 Poster session VI: Chemosensory developmentand Psychophysics IInvestigation of detection and pain thresholds at different sitesat the human nasal mucosa in response to electrical stimuliMandy Scheibe, Annika SchmidtSmell & Taste Clinic, Department of Otorhinolaryngology,University of Dresden Medical School Dresden, GermanyBackground: Previous investigations in humans suggestdifferences in the distribution of intranasal trigeminalchemosensitivity. The aim of the present study was to investigatethese topographical differences in the human nasal mucosa usingunspecific electrical stimuli. Material and Methods: A total of 27young, healthy volunteers participated (11 men, 16 women; age22-30 years). Detection and pain threshold of trigeminal stimuliwere investigated at 5 different sites at the nasal mucosa: anteriorseptum, posterior septum, lower turbinate, middle turbinate andanterior lateral nasal wall. Electrical stimuli were applied with aspherical electrode. Results: At the anterior parts of the nosesignificantly higher trigeminal sensitivity was found than at theposterior part. There was a similar distribution pattern of thesensitivity for detection and pain thresholds. Conclusions: Thepresent data suggest that there are topographical differences in thedistribution of trigeminal receptors at the human nasal cavity.Thereby it seems that the highest sensitivity is located in theanterior part. This finding is compatible with the idea that thetrigeminal system acts as a sentinel of the human airways withregard to toxic agents.#P256 Poster session VI: Chemosensory developmentand Psychophysics ITime-Intensity ratings of nasal irritation from pulsedhomologous alcoholsPaul M Wise, Kai Zhao, Charles J WysockiMonell Chemical Senses Center Philadelphia, PA, USARelatively few studies have focused on how nasal irritationchanges over time. To simulate the rhythm of natural respiration,subjects received 3-sec pulses of VOC (volatile organiccompound) interspersed with 3-sec pulses of clean air. Each trial,subjects received nine VOC pulses over 51 sec. Subjects ratednasal irritation from each pulse using magnitude estimation.Within a trial, compound and concentration were fixed.Compound (n-ethanol, n-butanol, and n-hexanol) andconcentration (four levels for each compound) varied across trials.Findings: 1) For all stimuli, rated irritation decreased over time(adaptation). Plots of log rated intensity versus elapsed time wereapproximately linear (intensity decreased by a fixed ratio per unittime). Interestingly, the slopes of intensity versus time functionsdiffered very little: Regardless of concentration and compound,rated irritation decreased by about 30 or 40% over the ninepulses. 2) For a given compound, the slopes of intensity versusconcentration (psychophysical) functions remained constantacross pulses. Overall intensity decreased over time, but the106 | AChemS Abstracts 2009

elationship between concentration and intensity remained thesame. 3) Across compounds, slopes of psychophysical functionsdiffered greatly. Differences among compounds in the slope ofpsychophysical functions are unsurprising, but serve as a positivecontrol of sorts for the lack of differences among compounds indynamics. In short, some aspects of the dynamics of nasalirritation may differ very little across VOCs. The basicmechanism of short-term adaptation may be the same for thecompounds studied. Regardless, these and other recent datasuggest that very simple models can describe some aspects ofperceptual dynamics quite well.#P257 Poster session VI: Chemosensory developmentand Psychophysics INasal biopsy assessment of veterinary students exposed toformaldehyde in anatomy classKaren K. Yee 1 , Tamika Wilson 1 , Ryan McDermott 1 , Edmund A.Pribitkin 2 , David Rosen 2 , Christopher Maute 1 , Pam Dalton 11Monell Chemical Senses Center Philadelphia, PA, USA,2Thomas Jefferson University Philadelphia, PA, USAInhaled formaldehyde has been linked to nasal irritation,inflammation and olfactory dysfunction and at highconcentrations to nasal tumors in animal and humanepidemiological studies. Occupational exposure to formaldehydein gross anatomy class from formalin-preserved cadavers is ahealth concern to both staffs and students. As part of our ongoingstudies to understand mechanisms underlying chemicalinduced chemosensory dysfunction, we examined nasal biopsies,taken from the upper aspect of the middle turbinate, from 15(5M, 10F) veterinary students (mean age = 24) at pre-exposureand after 20 weeks of formaldehyde exposure in anatomy class(approximately 4hrs/day, 4 days/week) and from 13 (5M, 8F)age-matched controls. Formaldehyde exposures (range 0.15-2.15ppm) of the veterinary students were monitored withformaldehyde-specific badges (3M). Histopathology of thesensory epithelium (i.e, pseudostratified, hyperplasia, squamousmetaplasia and erosion) was evaluated. In preliminary findings,biopsies of 5 veterinary students (33.5%) showed an increase inerosion after post-exposure compared to their pre-exposurebiopsies. In comparison, just 2 control biopsies (15.4%) exhibitedan increase in erosion compared to their initial biopsies. Thedegree of inflammatory infiltration will be analyzed to determineif histopathological changes correlates with inflammation andformaldehyde exposure levels. We also collected chemosensorythresholds, nasal nitric oxide levels, nasal cytology and nasallavage fluids, which will allow us to examine correlations betweenpsychophysics and neuropathology/inflammation. Assessment ofnasal biopsies provides an opportunity into understanding howchanges at the cellular/tissue level can manifest into chemosensorydysfunctions after chemical exposure.#P258 Poster session VI: Chemosensory developmentand Psychophysics IFunctional and Inflammatory Consequences of VeterinaryGross Anatomy Lab Enrollment: Effects of Formaldehydeon ChemosensationRyan D. McDermott, Tamika L. Wilson, Kara J. Blacker,Christopher Maute, M. Hakan Ozdener, Pamela H. DaltonMonell Chemical Senses Center Philadelphia, PA, USAOccupational exposure to pollutants and other toxic substanceshas been associated with impairment in human chemosensoryfunction. Formaldehyde, a ubiquitous air contaminant that occursfrom natural as well as man-made sources, is known to haveadverse health effects, including upper airway irritation. Theobjective of this study was to evaluate the chemosensory impactof repetitive exposure to formaldehyde. The experimental cohortfor this research was veterinary students working in a grossanatomy laboratory. Individual formaldehyde exposure wasrecorded through the use of passive dosimeters worn whilestudents were in the laboratory. Chemosensory function wasevaluated using a standard battery of tests prior to and throughoutthe duration of the three month exposure. Tests included odoridentification test along with odor detection thresholds forformalin, PEA, and l-carvone. Lateralization (irritation)thresholds were collected for formalin and a control irritant, n-butanol. Upper airway inflammation was evaluated using nasalnitric oxide (nNO) concentrations and analysis of inflammatorymediators from nasal lavage. All results were compared to a nonexposedcontrol group matched on age and gender. Exposureassociatedincreases in inflammatory biomarkers from nasal lavagefluid and nNO were correlated with significant alterations inchemosensory performance. Although the changes in theseyoung, healthy participants are likely reversible, these resultsemphasize the need for continued monitoring of individuals withlong-term employment in occupations where these types ofexposures will be incurred.#P259 Poster session VI: Chemosensory developmentand Psychophysics IDevelopment and Evaluation of the Monell OdorIdentification Task for the NIH ToolboxChristopher Maute 1 , Sara Lehmann 1 , Carly Jornlin 2 , WilliamParkes 2 , Christopher Grindle 2 , James S. Reilly 2 , AllisonSteinmeyer 1 , Jill Hersh 1 , Julie A. Mennella 1 , Pamela H. Dalton 11Monell Center Philadelphia, PA, USA, 2 Nemours/Alfred I.duPont Hospital for Children Wilmington, DE, USAThe National Institutes of Health (NIH) Toolbox initiative seeksto assemble brief, comprehensive assessment tools that will beuseful to clinicians and researchers in a variety of settings, with aparticular emphasis on measuring outcomes in longitudinalepidemiologic studies and prevention or intervention trials acrossthe lifespan. Monell’s involvement in the NIH Toolbox is todevelop tools to assess olfactory functioning in individualsbetween the ages of 3 and 85 years. We reported here on thedevelopment and preliminary analysis of the Monell OdorIdentification Task that was designed to be sensitive to thecognitive limitations of children. We tested 368 subjects who werebetween the ages of 3 and 17 years; 186 were tested at the MonellCenter and 182 at Nemours/A.I. DuPont Hospital. Subjects werepresented with 6 cards, each of which was affixed with a scratch-P O S T E R SAbstracts | 107

and-sniff sticker. For 55% of the children the odors on the cardswere lemon, coffee, Play-Doh TM , floral, bubble gum and peanutbutter; whereas for the remaining children (particularly thosewhose mothers reported they had peanut allergies), the odorswere the same with the exception that peanut butter was replacedby cinnamon. After smelling each card, the subject was then askedto identify the odor by pointing to 1 of 4 pictures. All but onechild (3 years) completed the task which took less than 5 minutes.Preliminary analyses revealed that there were significant effects ofboth age group and odor on identification (p

four (4 AFC) that they believe is most representative of thestimulus. Prior to testing the subject is presented with a picture ofeach of the odor stimuli on the LCD and they must name theobject. A correct or incorrect response is recorded by theexaminer. In order to keep the participants engaged in the task,one additional modification was implemented. Before testingbegan, each participant was allowed to choose their form ofreinforcement for correctly identifying an odor stimulus. Acorrect response would either 1) “virtually” burst one balloonfrom an array of 20 displayed on the LCD; or 2) add one “virtualballoon” to a bouquet of balloons on the screen. To evaluate theutility of this test, two groups of children 6-8 years old weretested as part of a larger battery of tests that included measures ofpostural sway and auditory function. The groups were part of alarger study examining the effects of environmental manganeseexposure on childhood development. Collection of the data isongoing; results of the study will be described in detail at themeeting. Supported by NIDCD grant DC6369.#P263 Poster session VI: Chemosensory developmentand Psychophysics IComparison of two different olfactory detection thresholdtests of the Sniffin’ SticksRebekka Zernecke 1 , Birgit Vollmer 1 , Jessica Albrecht 1,2 ,Anna M. Kleemann 1 , Katrin Haegler 1 , Jennifer Linn 1 ,Gunther Fesl 1 , Hartmut Brückmann 1 , Martin Wiesmann 1,31Department of Neuroradiology, Ludwig-Maximilians-Universityof Munich Munich, Germany, 2 Monell Chemical Senses CenterPhiladelphia, PA, USA, 3 Department of Radiology andNeuroradiology, Helios Kliniken Schwerin Schwerin, GermanyObjectives: The olfactory test battery Sniffin’ Sticks is a test ofnasal chemosensory function which is based on pen-like devicesfor odor presentation. It consists of three subtests: odor threshold,odor discrimination and odor identification. The detectionthreshold can be measured using two different odorants – n-butanol or PEA (phenylethyl alcohol). Both test batteries arecommonly employed in published studies, but there has neverbeen a formal comparison of values obtained using them. Thepurpose of this study was to compare two different olfactorydetection threshold tests (n-butanol and PEA). Methods: Bothtests were applied to a group of 78 healthy, normosmic subjects(41 male, 37 female). The experiment was divided into twosessions performed on two different days. The order of both testswas pseudo randomized. After each threshold test adiscrimination and identification test was conducted.Results: There were significant differences in odor detectionthresholds of PEA and n-butanol. The mean score of PEAdetection threshold and PEA TDI (threshold discriminationidentification) was significantly higher compared to n-butanol.Participants detected PEA at a lower concentration than n-butanol. No significant correlation between individual PEA andn-butanol thresholds was detected. Conclusion: Previous workregarding the test-retest reliability and validity of the Sniffin’Sticks was performed using the n-butanol threshold test only.The differences between both olfactory test batteries indicatethat a formal validation of Sniffin’ Sticks test with PEA asodorant for detecting the olfactory threshold may be required.#P264 Poster session VI: Chemosensory developmentand Psychophysics ILongitudinal study of olfactory preferences during childhoodFanny Rinck 1 , Melissa Barkat-Defradas 2 , Fanny Bourgeat 1 ,Catherine Rouby 1 , Moustafa Bensafi 11CNRS UMR 5020 Lyon, France, 2 CNRS UMR 5267Montpellier, FrancePleasantness is a prominent facet to the olfactory world.Whereas some aspects of odor hedonics are innate, others areformed during development. One question that is still debated inthe current literature is the early stages of development wherebysuch formation of odor preferences occurs. In the present studywe hypothesized that a critical time-window may be between 3and 5 years old, a period of life whereby the ability to detect,name and memorize odors significantly improves. The presentstudy was aimed at testing this hypothesis through a 3-years longlongitudinal experiment. Fifteen 3-years old children participatedto 3 experimental sessions from year 1 (2006) to year 3 (2008).Participants were first asked to complete a standardized Frenchtest of language and were then exposed to 12 odors (presented foraround 2 sec in a random order). After smelling each compound,they were asked to answer two questions: 1) Do you like ordislike this odor? and 2) Can you tell me what it is? Childrenwere filmed during the session, and both verbal and behavioralresponses were analyzed to give the most reliable measure ofhedonic responses. In line with previous findings, we observedthat general language abilities (production (p

we used two transgenic mouse lines, with Wnt1- and P0-Credriven reporters. A progressive developmental association ofNCDCs with taste papillae is observed in tongues of Wnt1-Crereporter mice (E12.5, 16.5, P1). Labeled cells are intenselydistributed in fungiform, foliate and circumvallate papillae.Brightly labeled cells are within the mesenchymal core of papillaeand in the basal lamina region underlying early taste buds. A fewlabeled cells are also seen in the epithelium of taste papillae at P1.In P0-Cre reporter tongue sections (E14.5, 16.5 and P10),numerous labeled cells are seen in clusters in the tongueepithelium (within papillae or between papillae) and mesenchyme.At P10, intensely labeled cells are observed in early taste buds.The distribution of labels for NCDCs in the developing tongue,taste papillae and early taste buds strongly implicates a neuralcrest contribution to papilla and taste bud development.#P266 Poster session VI: Chemosensory developmentand Psychophysics IImpact of Proportion on Configural Perception of OdorMixtures in a Newborn MammalGérard Coureaud 1 , David Gibaud 1 , Elodie Le Berre 2,3 , BenoistSchaal 1 , Thierry Thomas-Danguin 21Centre Européen des Sciences du Goût (CESG), CNRS-UB-INRA Dijon, France, 2 FLAVIC, INRA-ENESAD-UB Dijon,France, 3 current address: Unilever Food and Health ResearchInstitute Vlaardingen, NetherlandsConfigural perception of odor mixtures appears functional earlyin life. Recent results underline that after the learning of a binarymixture (AB) that blends in humans, newborn rabbits respondboth to the mixture and to its components. However, after thelearning of a single component they do not generalize to themixture. This suggests that they perceive more in the mixture thanthe odor of each constituent (Coureaud et al., Physiol. Behav.2008). Here, we pursued the assessment of their configuralperception of AB, with the aim to determine whether specificcomponent proportions of A and B elicit the perceptualemergence of an additional odor in AB. Starting from the initialcomposition of the AB mixture, we tested whether pups perceivedmixtures with weakly different proportions of A and B (A - B,A + B) either elementally of configurally. In Exp. 1, 17 pups (age:2d, 4 litters) were conditioned to A, and tested for their oralresponse to AB, A - B, and A + B. In Exp. 2, 2x20 pups (2d, 8 litters)were enforced to learn A - or A + , and respectively tested with A - ,A - B, AB, and A + , A + B, AB. In Exp. 3, 18 and 20 pups (2d, 8litters) were conditioned to A + B and tested for their response toA + , B or to A + B and AB. As expected, pups conditioned to A didnot respond to AB, but interestingly they responded to A - B andA + B (>45%; Exp. 1). Additionally, after learning of A - or A + ,newborns strongly responded to A - B or A + B (> 70%) but theirresponse remained poor to AB ( 90%) butsignificantly less to AB (50%). These results highlight the rabbitnewborn ability to discriminate between odor mixtures presentingslightly different proportions of odorants, and confirm theconfigural perception of certain odor mixtures by the younganimal.#P267 Poster session VI: Chemosensory developmentand Psychophysics ICorrelation between olfactory bulb volume and olfactoryfunction in childrenDorothee Buschhüter 1 , Martin Smitka 2 , Stefan Puschmann 1 ,Johannes Gerber 3 , Thomas Hummel 111Departments of Otorhinolaryngology Dresden, Germany,2Paediatrics Dresden, Germany, 3 Radiology Dresden, GermanyThe olfactory bulb (OB) is considered to be the first importantrelay station in odor processing. The aim of the present study wasto investigate whether and how the human bulb increases duringchildhood and youth. Involving a large number of subjects thepresent study also aimed to investigate a possible correlationbetween the OB volume and specific olfactory functions includingodor threshold, odor discrimination, and odor identification. Atotal of 87 randomly selected subjects (46 men, 41 women), aged 1to 17 years (mean age 8 years), participated in this study. None ofthem reported olfactory dysfunction. All participants received anotolaryngological investigation including a volumetric scan of thebrain (MRI), and lateralized olfactory tests. The history of allparticipants was taken in great detail to exclude possible causes ofsmell dysfunction. Volumetric measurements of the right and leftOB were performed by two independent observers by manualsegmentation of the coronal slices through the OBs using theAMIRA 3D visualization and modeling system (Visage Imaging,Carlsbad, USA). Significant correlations between left and right OBvolumes in relation to odor thresholds (left: r 51 =0.56; right:r 53 =0.63; p

#P268 Poster session VI: Chemosensory developmentand Psychophysics IPregnancy and Olfactory SensitivityE. Leslie Cameron 1 , Richard L. Doty 21Carthage College Kenosha, WI, USA, 2 Smell & Taste Center,University of Pennsylvania School of Medicine Philadelphia, PA,USAINTRODUCTION The purported role of hormones in olfactionhas led to the hypothesis that women should outperform men inolfactory tests and that olfactory changes should occur across themenstrual cycle and pregnancy. Although women do outperformmen on many tasks and there is evidence for changes in olfactorysensitivity across the menstrual cycle, the literature on pregnancydoes not provide strong support. A careful review of the literaturereveals that when present differences are often very small anddepend on many factors. This on-going study assesses olfactoryfunction in women across pregnancy. METHODS Sixteenpregnant women and 10 non–pregnant controls were each tested 3times. Women rated their “sense of smell” and pregnant womenreported odors to which they were particularly sensitive.Thresholds for phenyl ethyl alcohol were established using astandard staircase procedure, followed by 75 signal detection (SD)trials. RESULTS Pregnant women rated their sense of smellsignificantly higher during the first trimester compared to prepregnancyand the third trimester, but thresholds did not changeacross pregnancy nor differ from controls. Preliminary analysesrevealed no difference on SD trials across trimester nor pregnancystatus. However, early in pregnancy ~75% of women identified atleast one odor to which they were more sensitive, but nonementioned “rose”. CONCLUSIONS These results are consistentwith previous pregnancy studies demonstrating more consistentand larger changes in self-rating/report than in behavioralmeasures. Thus, although there are fluctuating levels of hormonesacross pregnancy, systematic changes in olfaction acrosspregnancy were not observed. The relationship betweenhormones and olfactory function and the role of odor on taskperformance is discussed.#P269 Poster session VI: Chemosensory developmentand Psychophysics IBeliefs About Health Effects from an Odor AlterSniffing of that OdorPatricia Bulsing 1 , Monique A Smeets 2 , Tyler Lorig 31Unilever Vlaardingen, Netherlands, 2 Utrecht University Utrecht,Netherlands, 3 Washington and Lee University Lexington, VA,USAJust as eye tracking has been used to monitor shifts in attention tovisual input, sniffing can be tracked to monitor attentional shiftsto olfactory input. We investigated whether a cover story abouthealth effects from an odor altered sniffing of that odor. Methods:63 Subjects were asked to smell the odors vanilla, citrus,ethylbutyrate, and the target odor Orange Flower Ether inrandom order and match each to one of four previously providedcover stories. There were three different groups based on coverstory of the target odor only: negative bias (NB: n= 22, “odor ischemical rest product”), positive bias (PB: n=20, “ aromatherapyproduct” ), and the neutral group (N; n=21, “standard odor”).Odors were rated on attributes such as pleasantness, intensity, anddangerousness on 7-point scales. Sniffing was measured via a nasalair pressure transducer. Results: Effects of bias manipulation onsniffing parameters were not significant (p >.05). What turned outto be important was whether subjects, after smelling the odor,believed the odor to be dangerous. A comparison between “odorbelieved to be dangerous” versus “odor believed to be safe”groups based on median split of the target odor danger ratingsrevealed a smaller area under the curve (p=.02) and shorterduration (p=.02) from the first sniff of the target odor in theformer relative to the latter group (with bias group as covariate).Conclusion: Odor sampling behavior or sniffing is not affected bya cover story about the odor’s possible health effects, only bywhether people believe it to be dangerous after smelling it,regardless of the cover story.#P270 Poster session VI: Chemosensory developmentand Psychophysics IRelationship between Odor Properties for Pleasant andUnpleasant OdorsAllana L. Goodman 1,2 , Jelena Djordjevic 1,21Montreal Neurological Institute Montreal, QC, Canada, 2 McGillUniversity Montreal, QC, CanadaRelationships between different odor properties have been studiedextensively, but whether different patterns characterize pleasantand unpleasant odors is unknown. We examined whether therelationships between perceived odor intensity, pleasantness,familiarity, and irritability differ for pleasant and unpleasantodors. Thirty healthy participants rated a set of 24 odors (halfpleasant, half unpleasant) on four odor properties. Each odor waspresented in three concentrations (weak, intermediate, and strong)for a total of 72 odors, and ratings were completed using a visualanalogue rating scale. Correlation between intensity andpleasantness was stronger for unpleasant than for pleasant odors,in addition to being in the opposite direction. Pleasantness wasstrongly correlated with familiarity for pleasant but not forunpleasant odors. Finally, irritability was strongly correlated withintensity for both categories of odors, whereas it was morestrongly correlated with pleasantness for unpleasant than forpleasant odors. These findings demonstrate that pleasant andunpleasant odors represent fundamentally different odorcategories and corroborate previous claims that pleasantness is aprimary dimension in olfaction.#P271 Poster session VI: Chemosensory developmentand Psychophysics ISlight Variations in Components Ratio affect OdorPleasantness of a Blending MixtureElodie Le Berre 1,3 , Noëlle Béno 1 , Gérard Coureaud 2 ,Patrick Etiévant 1 , Thierry Thomas-Danguin 11Flaveur Vision et Comportement du Consommateur, INRA-ENESAD-UB Dijon, France, 2 Centre Européen des Sciences duGoût, CNRS-UB-INRA Dijon, France, 3 current address: UnileverFood and Health Research Institute Vlaardingen, NetherlandsOdors rely mainly on the perception of odorants mixtures but arecommonly perceived as single undivided entities; nevertheless, theprocesses involved remain poorly explored. It has been reportedthat perceptual blending, based on configural olfactoryprocessing, can lead odorant mixtures to give rise to an emergentP O S T E R SAbstracts | 111

odor quality not present in the components. Furthermore, veryslight variations (just noticeable differences, jnd) in componentsconcentrations were shown to be sufficient to modify the odorquality of a blending mixture. In the present study, we set out toexamine whether jnd in components concentrations could alsoaffect the odor pleasantness of a blending mixture. We startedfrom the composition of a ternary target mixture of odorants inwhich an emergent pineapple odor has been evidenced for a givenconcentration of each component. Then, we set 4 concentrationlevels of each component that elicit jnd. Each combination oflevels was used to design sample mixtures that were deliveredusing a dynamic air-dilution olfactometer. Fifteen subjects(3 men, 19 to 26 years old) compared the intensity, typicality, andpleasantness of each sample mixture against the target mixture in apaired-comparison protocol. Statistical modeling of the resultsshowed that slight variations in components ratio did affectsignificantly odor pleasantness of the ternary mixtures. When theconcentration of one of the components increased, the mixturepleasantness decreased whereas an interaction between the twoother components was observed. These results underlined (i) thekey role of odorants concentrations ratio on the pleasantness of amixture odor and (ii) the human ability to discriminate betweenodor percepts induced by mixtures including even close odorantproportions.#P272 Poster session VI: Chemosensory developmentand Psychophysics IIdentification of odorants induced by stress anddeception in humansGeorge Preti 1,2 , Jae Kwak 1 , Christopher Maute 1 , Pamela Dalton 11Monell Chemical Senses Center Philadelphia, PA, USA,2Department of Dermatology, School of Medicine, University ofPennsylvania Philadelphia, PA, USABehavioral studies and anecdotal reports suggest that stressfulsituations create recognizable changes to human body odors. Theodor change may be related to increased levels of stress-relatedhormones. However, the identity of any stress-induced odorantshas not been reported. In this study, we recruited volunteers whothen went through a standardized mental stress procedure (TrierSocial Stress Test). The six most stressed individuals out of 18volunteers were selected based on their monitored heart rate,respiration, salivary cortisol and self-reported stress ratings.Axillary sweat samples were collected on cotton pads from eachunderarm area during stress and non-stress condition. These wereextracted, evaluated by sensory panels and analyzed by gaschromatography/mass spectrometry in order to identify thestress-associated odorants. Overall, the sensory panelistsdiscriminated the odor differences above chance (with 63%accuracy) between the samples collected during the stress sessionand the samples in the pre-stress session. The chemical analysesshowed that the levels of several endogenously produced odorantswere increased after the stress exposure.#P273 Poster session VI: Chemosensory developmentand Psychophysics IThe Recognition Point in Odor DetectionWilliam S. Cain, Roland Schmidt, J. Enrique Cometto-MuñizUniversity of California, San Diego La Jolla, CA, USAIf an investigator measures a threshold for odor detection,someone will ask, “What is the recognition threshold?” No onehas seriously measured that point, though some have polledsubjects and ventured estimates of when quality begins to emergeover mere detection. Some have figured it to occur at lowmultiples of the detection threshold, such as 2x or 5x. Thoughreasonable, such estimates need an operational definition. Thepresent research affords a way to extract information onrecognition from 1000’s of confidence judgments per odorantgathered during forced-choice testing of detection in manysubjects. The ratings range from 1 (very low confidence) to 5(very high confidence). One can chart the distributions of theratings, i.e., frequency of each level vs. concentration, as isoconfidencecontours. The distributions have surprisingly uniformvariance within odorants. The data encourage a definition:The recognition point corresponds to the concentration at themedian of the distribution for “high confidence.” For someodorants, the point occurs when performance in detection hasbegun to converge on perfection. For others, it occurs at a lowerpoint on the detection function. Differences will depend upon thedistinctiveness (“brightness”) of quality. For the fruity odorantsd-limonene (orange rind), n-butyl acetate (banana), and t-butylalcohol (blueberry), the point occurs just twofold above thedetection threshold. For the less bright material, ozone (electricarc odor), it occurs sixfold above. As long as confidence ratingsco-exist with measures of detection, one can actually use anydesired level of confidence to specify recognition points.Distributions of high and very high confidence within and acrossodorants can serve as iso-recognition contours.#P274 Poster session VI: Chemosensory developmentand Psychophysics ITime encoded in smellKinneret Weissler 1 , Shulamith Kreitler 1 , Noam Sobel 21Department of Psychology, Tel-Aviv University Tel-Aviv Israel,2Department of Psychology, Tel-Aviv University Tel-Aviv Israel,3Department of Neurobiology, Weizmann Institute of ScienceRehovot IsraelOdor perception is bound by the primary dimensions of odorintensity and odor pleasantness, that have both beensystematically linked to odorant molecular structure. However,higher-order dimensions of olfactory perception remain largelyunexplored. Here we set out to ask whether humans can put atime label on an odor (“how long has this milk been open?”),or in other words, ask whether “time” is a dimension in smell.Considering that materials break-down over time, wehypothesized that as more kinds of molecules are added to anodor mixture, it will be perceived as older. Using a visualanaloguescale (VAS), 20 subjects (age

pleasantness (r=.275 p=.006), whereby worse smells smelled older.Repeated measures regression analysis, with “time” as adependent and “intensity” and “pleasantness” as covariates,provided no significant results. However, the means of mixturelevels 1 to 4 was in the expected direction, as revealed by a trendin the regression analysis excluding level 5 (F=3.28, p

#P278 Poster session VI: Chemosensory developmentand Psychophysics ICrossmodal interactions between odors and abstract symbolsHan-Seok Seo 1 , Artin Arshamian 1,2 , Kerstin Schemmer 3 , IngeborgScheer 4 , Thorsten Sander 3 , Guido Ritter 3 , Thomas Hummel 11Smell and Taste Clinic, University of Dresden Medical SchoolDresden, Germany, 2 Department of Psychology, StockholmUniversity Stockholm, Sweden, 3 Department of Home Economicsand Nutrition Science, Münster University of Applied SciencesMünster, Germany, 4 Dasign GmbH Darmstadt, GermanySo far, in many crossmodal studies between vision and olfaction,verbal labels, colors, or pictures have been used as visual cues, allof which elicit strong contextual backgrounds, whereas little isknown about the relationship between abstract symbols andodors. The aim of this study was to investigate the crossmodalassociation of an “abstract symbol,” designed for representationof an odor, with its corresponding odor. In other words, weexplored the application of an abstract symbol for expression ofan odor via an extension of the Stroop effect (congruence/incongruence paradigm). Based on the result of an odor-symbolassociation test, two abstract symbols associated with rose orcheese odor were selected. Two different odors representing“rose” and “cheese” were applied with three types of visual cues(blank screen, and two abstract symbols for rose and cheeseodors, respectively), followed by psychometric ratings (olfactoryintensity and hedonic response) and recording of event-relatedpotentials. When the odors were presented with their congruentabstract symbols, the hedonic responses of rose and cheese odorswere most pleasant for rose odor and most unpleasant for cheeseodor. The event-related potential latencies of peaks were also theshortest at all electrode sites tested on condition that the cheeseodor was provided with its congruent symbol. In conclusion, ourfindings demonstrate that an abstract symbol may affect olfactoryperception, and indirectly suggest that an abstract symbol couldrepresent its corresponding odor.#P279 Poster session VI: Chemosensory developmentand Psychophysics IHow big is the gap between detection and recognition ofaliphatic aldehydes?Matthias Laska, Anna RinghLinkoping University Linkoping, SwedenIt is widely agreed that two different measures of olfactorysensitivity can be distinguished: a detection threshold, defined asthe lowest concentration at which an odorant can be detected ordiscriminated from a blank stimulus, and a recognition threshold,defined as the lowest concentration at which an odorant can beassigned a recognizable quality or discriminated from anotherodorant. It is further widely agreed that the detection threshold islower than the recognition threshold. Surprisingly few studies,however, have investigated the magnitude of the difference inconcentration between olfactory detection and recognitionthresholds. It was therefore the aim of the present study todetermine olfactory detection thresholds for five aliphaticaldehydes (C4-C8) in a group of 16 human subjects, and to assessthe ability of the same subjects to discriminate between the sameodorants presented at different concentrations above theirindividual detection thresholds. We found that as a group thesubjects significantly discriminated between 4 of the 10 odorantpairs when presented at a factor of 100, and 7 of the 10 odorantpairs when presented at a factor of 1000 above the individualdetection thresholds. The 3 remaining odorant pairs were notdiscriminated above chance level even when presented at a factorof 1000 above detection threshold. However, single subjectssuccessfully discriminated between certain aldehyde pairspresented at a factor as low as 3 above detection threshold.Further, a significant negative correlation between discriminationperformance and structural similarity of the aldehydes tested wasfound. The results demonstrate that the gap between detectionand recognition of aliphatic aldehydes is odorant pair-dependentbut – at the group level – spans at least a factor of 100.#P280 Poster session VI: Chemosensory developmentand Psychophysics IComparison of odor threshold for phenylethylalcoholand butanolFranziska Krone, Kornelia Lange, Ilona Croy, Thomas Hummel1 Dresden, GermanyAim of the study was to compare the results of odor thresholdtest using different number of dilution steps, separately forbutanol and phenylethylalcohol (PEA). A total of 125 subjectsparticipated (30 patients with olfactory dysfunction, 95normosmic controls). In 2 sessions the olfactory threshold forbutanol and PEA was examined with 8 (wide step method) and 16(narrow step method) dilutions using felt tip pens. Test time wasshortened by approximately 2 minutes and remained moreconstant when using the wide step method. Butanol and the PEAthreshold were not significantly different; in addition, a significantcorrelation was found between thresholds for the two odors(r=0.57, p

utyl, hexyl, and octyl benzene). We employed dynamicolfactometry, natural odor sampling (sniffing), a three-alternativeforced-choice procedure against carbon-filtered air blanks, and alarge, tightly controlled, vapor stimulus source quantified via gaschromatography. Concentration-detection, i.e., psychometric,functions, from which odor detection thresholds (ODTs) can bedetermined, constituted the outcome of interest. Among ketones,ODTs decreased from acetone to 2-heptanone, remainingconstant for 2-nonanone. Among alkylbenzenes, ODTs decreasedfrom toluene to butyl benzene, then increased for hexyl andfurther for octyl benzene. These ODT trends resembled thosefound in the literature but the absolute ODTs were consistentlyamong the lowest previously reported. Interindividual variabilityof ODTs amounted to about one order of magnitude. Theoutcome provides additional support to the key role played inodor potency by physicochemical parameters governing thetransfer of the odorant from the vapor phase (where it enters thenose) through the various biophases (from the nasal mucus to theolfactory receptor environment), but it also indicates that, at somepoint, molecular dimensions begin to put a limit, and even reverse,the gain in olfactory potency observed with increasing carbonchain length. Supported by grant number R01 DC002741 formthe NIDCD, NIH.#P282 Poster session VI: Chemosensory developmentand Psychophysics ICigarette Smoking and the Olfactory Detection of CyanideJeneca J. Dovey, David E. HornungSt. Lawrence University Canton, NY, USASome organic chemists of a bygone era claimed smoking waslinked to an increased sensitivity to cyanide and so they justifiedsmoking because cyanide exposure was a profession hazard.The purpose of this study was to text this claim. Smokers andnonsmokers between the ages of 18 and 22 were ask to rate theintensity of a series of odors using the Green Scale (ChemicalSenses 21:323-334, 1996). Olfactory threshold measurements werealso determined for four odorants. Included in the odorants usedfor the intensity ratings were almond oil, ground-up peach pitsand trans-2-hexenal. Almond was included because it has acyanide-like smell, peach pits because they contain cyanidecompounds and trans-2-hexenal because it closely resembles themolecular structure of cyanide. Two of the odors used for thethreshold measurements were almond oil and trans-2-hexenal.Confirming what has been reported in many other studies, on theaverage, smokers gave lower intensity ratings and had higherthresholds compared to nonsmokers. However the intensityratings for trans-2-hexenal were not as reduced when compared tothe ratings for the other odorants and its threshold was notreduced by smoking. As a possible explanation for thisobservation, perhaps the cyanide like compounds found in somecigarettes are facilitating olfactory detection for this compoundand this facilitation offsets the overall decrease in olfactory abilitythat often accompanies smoking. In conclusion, although theremay be some validity in the claims of the organic chemists, theseresults suggest they would have been even better at detectingcyanide if they had not smoked at all.#P283 Poster session VI: Chemosensory developmentand Psychophysics IRetronasal olfaction influences swallowingMyriam Ebnoether 1 , Antje Welge-Luessen 1 , MarkusWolfensberger 1 , Thomas Hummel 21Dept. of Otorhinolaryngology, University Hospital Basel,Switzerland, 2 Smell & Taste Clinic, University of Dresden MedicalSchool Dresden, GermanyObjectives: Identical ortho- and retronasal stimuli are processeddifferently. Since retronasal odorant perception is stronglyassociated with food intake and flavour, an influence of retronasalstimulation on swallowing can be assumed. It was the aim of ourstudy to evaluate the impact of retronasal olfaction onswallowing. Subjects and Methods: Fifty normosmic andnormogeusic subjects (23 male, 24 female, mean age: 24 .2 years,range: 18-42) took part in the study. Olfactory stimuli (vanillin,40 % vol/vol) were presented randomized ortho- and retronasally(8 stimuli each) using a computer-controlled olfactometer.Simultaneously a sweet taste (glucose) was continuously deliveredthrough a taste dispenser which was kept within the mouth.Ultrasound examination of the mouth floor was continuouslyrecorded on a videotape to monitor swallowing activity. Thevideotapes were evaluated by one of the authors´ blindedconcerning place of stimulation (ortho- vs. retro). Results: Afterretronasal stimulation swallowing not only occurred faster(7.49 vs. 9.42s; p

measures ANOVA demonstrated a significant interaction betweengroups and pre-/post-conditioning A1 detection thresholds; theExperimental group demonstrated a significant increase and theControl group a significant post-conditioning sensitivity decrease,relative to pre-conditioning. Re-testing of olfactory sensitivity toA1 two months post-conditioning indicated no differencebetween the two groups. Taken together, these data demonstratethat the olfactory system exhibits rapid plasticity with thefunctional benefit of a sharp and odorant specific increase inabsolute detection threshold.#P285 Poster session VI: Chemosensory developmentand Psychophysics IEffects of sub-threshold odorants on rapid olfactoryadaptation in human observersRyan R. Keith 1 , Swati Pradeep 1 , Erica M. Rodriguez 1 , KatherineE. Boylan 1 , Danielle A. Broome 1 , Neal R. Delvadia 1 , David W.Smith 1,21Dept. of Psychology, University of Florida Gainesville, FL,USA, 2 University of Florida Center for Smell and TasteGainesville, FL, USAIn previous presentations we have described use of a novelpsychophysical technique for estimating the onset time course ofperceptual odor adaptation in humans. The premise of thetechnique is that extended presentation of an odorant willproduce adaptation, decreasing the sensitivity of the receptor andincreasing thresholds for a brief, simultaneous target odorantpresented at various time-points after the adapting stimulus onset;where both the adapting odorant and the target odorant are thesame (i.e., self adapting). Those results suggested that perceptualodorant adaptation was measureable within 100-200 ms afterstimulus onset. In those initial studies, the adapting odorantconcentration for each subject was set to twice the baselinethreshold for the 600-ms target (i.e., the same level relative tothreshold). In this presentation, using the same stimulusparadigm, we report changes in perceptual adaptation collectedwith the adapting odorant set to different subthresholdconcentrations levels. To characterize the effect of adaptingodorant level we used a liquid-dilution olfactometer to estimatetwo-bottle discrimination thresholds for brief (600 ms)presentations of vanilla odor; 13 volunteers (ages 18-21) served assubjects. Adapting odorant concentration levels were then set to0.25, 0.5, 0.75 and 1 times threshold concentration for each subjectand threshold for the 600-ms target was measured as a function ofthe relative delay between the onset of the adapting stimulus andthe onset of the target. The results demonstrate that significantincreases in odorant sensitivity were evident even at subthresholdadapting odorant levels. The time course of this subthresholdadaptation was similar to that measured with suprathresholdadapting odorants.#P286 Poster session VI: Chemosensory developmentand Psychophysics IUpdate on Racial and Gender Differences in Odor PerceptionCharles J. Wysocki 1 , Danielle R. Reed 1 , Doron Lancet 2 , YehuditHasin 2 , Jennifer Louie 1 , Lisa Oriolo 1 , Fujiko Duke 11Monell Chemical Senses Center Philadelphia, PA, USA,2Weizmann Institute of Science Rehovot, IsraelFor the past four years we have been screening African-Americanand Caucasian men and women for sensitivity to a select group ofodorants, viz., 5-a-androst-16-en-3-one (androstenone; having aurinous or sandalwood odor), amyl acetate (banana- or pear-likeodor), Galaxolide (musky), isovaleric acid (sweaty), 3-methyl-2-hexenoic acid (3M2H; sweaty), pentadecalactone (musky), benzylsalicylate (balsamic), muscone (musky), Jeger’s Ketel (woody,amber), 2-nonenal (unpleasant, fatty), skatole (fecal) and geosmin(earthy), selected because some people have a specific anosmia tothe odorant. Psychophysical testing is performed in a singlesession and DNA is obtained for subsequent analysis. Phenotypicdifferences between the two racial groups and between men andwomen have been observed. Caucasians have a significantlygreater rate of specific anosmia to androstenone (7%) than doAfrican-Americans (0%). The opposite is true for benzylsalycilate (Caucasians, 22%; African-Americans, 35%).Disregarding race, men exhibit higher rates of specific anosmiasfor amyl acetate (3% vs 0%), Jeger’s Ketel (7% vs. 2%) andandrostenone (10% vs. 3%) than do women. Among individualswho can smell the odorants, Caucasians have higher olfactorydetection thresholds for 3M2H (0.0058 w/v), Galaxolide(0.0407% v/v) and isovaleric acid (0.0020% w/v) than doAfrican-Americans (respectively, 0.0024%; 0.0092%; and0.0006%). Data collection continues and the above is subjectto change.#P287 Poster session VI: Chemosensory developmentand Psychophysics ITaste cell specific over-expression of BDNF leads to multiplefold increase of expression levels of BDNF and increased sizeand number of taste budsIrina Nosrat 1 , Shailaja Kishan Rao 1 , Weikuan Gu 1 , RobertMargolskee 2 , Christopher Nosrat 11University of Tennessee Health Science Center Memphis, TN,USA, 2 Mount Sinai School Medicine New York, NY, USABrain-derived neurotrophic factor (BDNF) is the most potentneurotrophic factor in the taste system during development, and isalso expressed in taste cells of adult mice. We over-expressedBDNF using a promoter for alpha-gustducin to study the roles ofBDNF in the adult taste system. Gustducin is normally expressedin type II receptor cells that also express G-protein coupled tastereceptors. Taste buds were isolated using laser capturemicrodissection from circumvallate papillae of six weeks oldgustducin-BDNF taster mouse lines. RNA was isolated and realtime PCR analysis revealed a six-fold increase of BDNF in twotransgenic mouse lines. We also employed immunohistochemistryon taste papillae of gustducin-BDNF mice using Troma-1antibody which identifies taste buds. In addition, we analyzedtongue surface and papillae morphology using scanning electronmicroscopy. Circumvallate papillae are wider in gustducin-BDNFcompared to wild-type mice. Additionally, circumvallate tastebuds in high BDNF expressing transgenic mice are wider and116 | AChemS Abstracts 2009

taller compared to wild-type mice. Fungiform taste bud size andpapillae number are also significantly higher in high BDNFexpressing transgenic mice compared to wild-type mice. We arecurrently performing microarray analysis to examine geneexpression profile in Gust-BDNF mice.#P288 Poster session VI: Chemosensory developmentand Psychophysics IDreams and Smell - The Impact of Nocturnal OlfactoryStimulation on DreamsBoris A. Stuck 1 , Desislava Atanasova 1,2 , Michael Schredl 21Department of Otorhinolaryngology, Head and Neck SurgeryMannheim, Germany, 2 Central Institute of Mental HealthMannheim, GermanyOnly a limited number of trials is available regarding the impactof external stimulation on dreams. An incorporation of stimuliinto dreams is depending on the intensity and significance of thestimulus. Olfactory stimuli have hardly been investigated in thiscontext. Aim of the study was to assess whether olfactory stimuliare incorporated into dreams and whether they influence dreamemotions. 15 female volunteers were investigated during 30 nights(first night for adaptation). Standardized awakenings wereperformed during REM sleep under constant monitoring of sleepstages. Subjects were exposed to non-odorous control, a positive(PEA, 20%) and a negative odor (H2S, 4 ppm) for 10 secondseach during REM sleep in a randomized fashion via a computerolfactometer. After awakening, subjects were advised to reportdream content in a standardized fashion and to rate dreamemotions (positive and negative) on a four digit scale (0 to 3: no tostrong feelings). Dreams were analyzed by an independentinvestigator for potential incorporations. The overall emotionalcoloration was calculated. Direct incorporation was detected inone dream only (neutral condition), indirect incorporation(contents associated with smelling) was detected in four dreamswithout relation to stimulus condition. Mean emotionalcoloration after control stimulation was slightly positive (+0.5).After negative stimulation, it was shifted to negative values (-0.4)while the mean emotional coloration was more positive afterpositive stimulation (+1.2), the difference reaching statisticalsignificance. With olfactory stimulation direct incorporation ofolfactory stimuli into dreams does not seem to appear. In contrast,the emotional coloration of dreams can be significantly influencedaccording to the hedonic aspect of the stimulus.#P289 Poster session VI: Chemosensory developmentand Psychophysics IEffects of Septoplasty — A Pre- and Postoperative Studyon Trigeminal Sensitivity and Olfactory PerformanceBenno Schuster 1 , Stefanie Schulze 1 , Christian A. Mueller 21Smell & Taste Clinic, Dept. of ORL, University of DresdenMedical School Dresden, Germany, 2 Dept. of ORL, MedicalUniversity of Vienna Vienna, AustriaSurgery of the nose may have an impact on olfactory performanceand trigeminal sensitivity. Aim of the present study was toinvestigate the actual extent of these effects in clinical practice.Normosmic healthy subjects (n=43) and patients who underwentseptoplasty (n=38) were tested immediately before and up to threemonths after surgery, this interval was matched in the controlgroup. In both sessions olfactory performance and trigeminalsensitivity were assessed using electrophysiological (event-relatedpotentials [oERP], [tERP], stimuli: H 2 S and CO 2 ) as well aspsychophysical methods (odor identification test, CO 2 detectionthreshold, CO 2 pain threshold, detection of stimulus duration forCO 2 ). Ability to identify odors was superior in the control group(p=0.026). There was no significant group effect regarding oERP,furthermore no interaction “pre/post” * “group“ (p=0.60).Concerning trigeminal detection threshold and pain threshold nodifferences were observed among groups. In addition, a relativedecrease in N1 amplitudes (p=0.004) combined with a relativeincrease in P2 latencies (p=0.088) was present in the patient groupafter septoplasty. However, no significant difference between thefirst and second session could be detected. Trigeminal sensitivitydoes not seem to differ among the more and less obstructed sideof nose. Furthermore the results give reason to presume that thereis a difference in trigeminal sensitivity between patients andcontrols. Even though septoplasty is a matter of massivemanipulation of nasal mucosa, these findings indicate no majoreffect of surgery on olfactory performance or intranasaltrigeminal sensitivity.#P290 Poster session VI: Chemosensory developmentand Psychophysics IPutative Human Pheromones Increase Women’s ObservedFlirtatious Behaviors and Ratings of AttractionJames V. Kohl 1 , Linda C. Kelahan 2 , Heather Hoffmann 21Stone Independent Research, Inc. Phoenix, NY, USA,2Knox College Galesburg, IL, USAMammalian conditioning paradigms suggest that androstenolconditions hormonal effects in women that are unconsciouslyassociated with the potential behavioral affects of androsterone.We evaluated individual video-taped fifteen-minute interactionsfourteen ovulatory-phase women during a cooperative task.During the task, our male accomplice wore either a standardizedandrostenol / androsterone mixture diluted in propylene glycol,or he wore the diluent (i.e., propylene glycol). Sandalwood odorwas added to the mixture and to the propylene glycol to keep ouraccomplice blind to his condition. Women were more likely todisplay flirtatious behaviors when our accomplice was wearing themixture than when he wore the diluent (t(12) = 4.38, p

#P291 Poster session VI: Chemosensory developmentand Psychophysics IEffects of Video Game Console and Snack Type on SnackConsumption During PlayJonathan Kolks, Tim Wright, Bryan RaudenbushWheeling Jesuit University Wheeling, WV, USAPast research has shown the effects of distraction on food intake.The present study examined the effects of snack type (healthy,unhealthy, and neutral) on snack consumption while playing avariety of video games. Participants wore a device to measure theamount of their movement during the session. For one of theconditions, the participants played the Nintendo Wii’s boxinggame that comes equipped on Wii Sports. The participantswarmed-up for five minutes and continued to play the game forthe duration of the fifteen-minute session. For another condition,the participants played the Xbox version of Rocky Legends onexhibition mode. The participant warmed-up for five minutes andthen continued to play for the duration of the fifteen-minutesession. The third condition was used as a control, and theparticipants sat in an empty room for the duration of fifteenminutes. Before and after the video game play or the controlsession, the participants’ physiological measurements were taken.Three different snack types (healthy, unhealthy, and neutral) wereleft in the room. For each participant 38 grams of pretzels, 160grams of carrots, and 100 grams of M&M’s were presented.Overall activity level was greatest in the Wii condition indicatingsignificantly more calories burned, and participants ate less in thatcondition. Although both the Wii and X-Box conditions showedless snack consumption in general, participants ate more healthysnacks in the Wii condition.#P292 Poster session VI: Chemosensory developmentand Psychophysics IEffects of Peppermint Scent Administration on IncreasingNintendo Wii Guitar Hero PerformanceRyan Hunker, Tim Wright, Kristin McCombs,Laura Bruno, Bryan Raudenbush, Jonathan KolksWheeling Jesuit University Wheeling, WV, USAPrevious research has shown the benefits of peppermint in avariety of situations. The current study used 60 participants tocompare performance, mood, and perceived task load in videogame play. Participants were randomly assigned to either theexperimental (peppermint scent administration) condition orcontrol (no scent) condition. Each participant played 5 songs onGuitar Hero III on the Nintendo Wii game system on 3occasions. Analyses were performed to determine effects ofpeppermint scent administration on learning, attention, mood,and perceived workload using appropriate ANOVA techniques.The results show that participants performed significantly betterin the peppermint scent administration condition and felt theirmental demand and effort throughout the songs were less thanthe control group. These results provide further evidence ofpepperment scent administration to enhance learning andperformance.#P293 Poster session VI: Chemosensory developmentand Psychophysics IDeposition of inhaled particles in the olfactory regionin rat and human nasal cavities during breathingJianbo Jiang, Kai ZhaoMonell Chemical Senses Center Philadelphia, PA, USAInhalation of airborne particles represents another route of masstransport that may directly expose olfactory neurons toaerosolized chemicals: odorants or toxic agents. Furthermore,insoluble nano-particles deposited in the rat olfactory region cantranslocate to the brain via the olfactory nerve. Although therehave been abundant in-vivo, in-vitro experiments and numericalstudy of aerosol deposition in the nasal cavity of laboratoryanimals, there is limited information about the effects ofanatomical difference on the aerosol deposition and to whichextent animal data can be extrapolated to humans. In this study,the deposition of nano to coarse particles (1nm~10um) in humanand rat nasal cavity was numerically investigated and comparedunder steady inspiratory flows ranging from restful breathing tostrong sniffing. The results showed that the deposition rates andpatterns strongly depended on particle size, flow rates and theanatomical differences between the species. With the increase offlow rate, the deposition rate decreases for nano-particles,however increases for coarser particles. In general, the rat nasalcavity has much higher deposition efficiency than human. Atrestful breathing, the deposition rate of nano-particle (3nm) was82%(25%) and 31%(2%) in the rat and human nasal cavities(olfactory region) respectively. For coarse particle (4um), thedeposition rate in rat was 79% and reduced to 6% in human.We further perturbed the nasal valve and olfaction region in ourhuman model and demonstrated more significant impact on thedeposition rate and pattern in the olfactory region than in thewhole nasal cavity. These results warrant the caution whentranslating aerosol deposition data derived from laboratoryanimals to human or to a specific individual.#P294 Poster session VI: Chemosensory developmentand Psychophysics IThe Effects of Orally Administered Capsaicin on Rat Taste BudVolume and Papillae Morphology Throughout DevelopmentKaeli K Samson, Suzanne I SollarsUniversity of Nebraska Omaha Omaha, NE, USAAfter chorda tympani nerve transection, there is a permanent anddrastic reduction in the number of taste buds when rats receivethe surgery as neonates, but not as adults (Sollars, 2005).Additionally, neonatal rats experience a greater decrease in tastebud volumes than adults after lingual nerve transection, howeverafter 50 days, neonates’ taste buds regenerate to their normal size(Gomez & Sollars, 2006). Because capsaicin is known to be aneurotoxin to lingual fibers in fungiform papillae (Nagy, et al.,1982), this chemical was used to determine if orally administeredcapsaicin yields similar effects on the tongue as those observedwith lingual transection. Female Sprague-Dawley rats were given2% of their body weight of either a 15% sucrose solution (SUC)or a capsaicin (.0033 mM) in 15% sucrose solution (CAP) everyday for 36 days. The neonatal group began treatment on postnatalday 5 (P5), while the adult group began treatment on P45.Neonates were administered solutions by hand using a cottontippedapplicator until P12, and then via a pipet until P24. All118 | AChemS Abstracts 2009

animals over the age of P24 were given solutions using a drinkingtube. Animals were sacrificed 2 days after their last treatment toobserve immediate effects of the treatment. Contrary to whatmight be expected given previous research, adult rats’ taste budswere more susceptible to capsaicin than neonates. Specifically,adults treated with CAP had significantly smaller taste buds 2days post treatment than adults treated with SUC. Such an effectwas not observed in neonates. Tongues were also analyzed 50 dayspost treatment to identify any possible regeneration of volumes,and surface analyses were performed at both 2 and 50 day timepoints to determine papillae count and morphology.#P295 Poster session VI: Chemosensory developmentand Psychophysics ICompetitive Effects of GSP and IX Nerve Transection onthe Maturation of CT Terminal Field Volume in theNucleus of the Solitary TractSara L Dudgeon, David L HillUniversity of Virginia Charlottesville, VA, USANeural competition among multiple inputs can affect theorganization of circuits in many sensory systems; however, thishas not been examined in the developing gustatory system. Thedegree of overlap among the greater superficial petrosal (GSP)nerve, the glossopharyngeal (IX) nerve, and the chorda tympani(CT) nerve terminal fields in the rostral nucleus of the solitarytract (NTS) is greatest early in development and decreases asanimals age to adulthood. To assess the effects of lack ofcompetition from the GSP and IX on the development of the CTterminal field, we sectioned the GSP and the IX at postnatal day15 (P15), P25 or P65. At 35 days post nerve section, the CT waslabeled and its terminal field was subsequently imaged andanalyzed. The results show that sectioning GSP and IX at P15results in a CT terminal field volume at adulthood that is similarto P15 controls and much greater than that of adult, uncutanimals. Therefore, the CT terminal field does not reorganize andprune back as it does in normal development when competitiveinfluences from GSP and IX are removed. Animals in which GSPand IX were cut at P25 or P65 also have CT terminal fieldvolumes comparable to P15 controls. This indicates that the CTnerve remains plastic into adulthood and is still subject to theeffects of competition. Preliminary evidence shows no changes inperipheral function of the CT nerve prior to GSP and IXregeneration, and significant loss (or absence) of palatal andposterior tongue taste buds at 30 days post nerve section. Thesestudies provide evidence that competition between individualinputs to the gustatory system plays a role in organizing theterminal fields.#P296 Poster session VI: Chemosensory developmentand Psychophysics IPostnatal development of trigeminal neuronal sensitivity tocapsaicin, nicotine, and innocuous coolingJiang Xu 1 , Valery Audige 2 , Nancy Rawson 3 , Bruce Bryant 11Monell Chemical Senses Center Philadelphia, PA, USA,2University of Pennsylvania Philadelphia, PA, USA, 3 Wellgen, Inc.North Brunswick, NJ, USAChanges in behavioral repertoire that occur over the course ofmaturation may reflect changes in peripheral neuronalpopulations. We examined trigeminal neuronal sensitivity inneonatal (2-3 day) and adult (5 week) rats to capsaicin (CAP,200nM), nicotine (NIC,100uM) and cooling (31.5 to 18C) usingintracellular calcium responses as an index of neuronalsensitivity. The overall proportions of neurons sensitive to each ofthe stimuli remained the same over 5 weeks of development.However, the proportion of different subtypes of neonatal andadult neurons sensitive to 1, 2 or 3 of the stimuli changed.Percentages were calculated on the basis of total number ofneonate or adult neurons tested (n=304 and 580) and sorted intosubtypes responsive to none,1,2, or 3 stimuli. In nicotine-sensitiveneurons, the proportion of CAP-sensitive cells was similar inneonates and adults. However, the proportion of cells sensitive toboth cooling and nicotine was higher in neonates than adults. Thisdifference between neonates and adults was most pronounced inthe proportion of cool-sensitive neurons also responsive tocapsaicin (8.5% vs 4.4%, respectively). Consistent with neonatalbehavioral aversion to cooling, these neurons are likelynociceptors that are also sensitive to innocuous cooling. Thecapsaicin dose-response function differed insignificantly ( t-test,p=0.12) in terms of EC50 in the two age groups (adult, 72.5±4nM,n=137; neonate, 55.6±10.9nM, n=112), while the S-nicotineconcentration (0.1-1000uM) response function was nearlyidentical in neonatal and adult trigeminal neurons. Our datasuggest that changes in neuronal subtypes may account forchanges in behavioral phenotype and for some purposes, neonataltrigeminal neurons may not be a good model for neuronalresponse patterns of the adult.#P297 Poster session VI: Chemosensory developmentand Psychophysics IDevelopment of the olfactory organ in fish: a comparisonAnne Hansen 1 , Peter Bartsch 2 , Eckart Zeiske 31University of Colorado Denver, CO, USA, 2 HumboldtUniversity Berlin, Germany, 3 University of Hamburg Hamburg,GermanyLocation and shape of the olfactory organ as well as structure anddevelopment of the olfactory epithelium (OE) vary greatly in rayfinnedfish (Actinopterygii). There is still considerable lack ofinformation regarding the development of the olfactory organ inmany basal taxa. This information is crucial for reconstruction ofthe evolution of this sensory system and the phylogeny ofosteognathostomes (the monophyletic group of osteichthyanfishes and tetrapods). In this study we examined the developmentof the olfactory organ in “primitive” groups that are close to thedichotomy of ray-finned fishes and lobe-finned fishes andtetrapods. We employed LM, TEM and SEM methods andcompared the development of the olfactory organ in Polypterus(bichir) to that of Acipenser (sturgeon) and teleosts. Our resultsindicate the following plesiomorphic (primitive) character statesin bichirs: The primary olfactory pit is formed by invagination ofP O S T E R SAbstracts | 119

the epidermal and the subepidermal layer (as in Acipenser andXenopus). The incurrent and excurrent nostrils derive from asingle primary opening (as in Acipenser and many teleosts). TheOE derives from an epidermal and a subepidermal layer (as inAcipenser and Xenopus). Apomorphic (derived) features are aninternal lumen as primordium of the future olfactory chamber.A subepidermal layer gives rise to the OE (as in teleosts). As tothe origin of the supporting cells in Polypterus we assume acombination of plesiomorphic and apomorphic characters.We conclude that Acipenser and Xenopus exhibit the most widelydistributed features among basal gnathostomes and thus ancestralosteichthyan character states in the development of the olfactoryorgan. Polypterus and teleosts both show a mixture ofplesiomorphic, apomorphic, and probably convergentlyderived features.chloride, sodium bromide, potassium chloride, ammoniumchloride, calcium chloride, sodium nitrate, sodium sulfate, sodiumsaccharin, sodium acetate and sodium benzoate; which togetherencompass salty, bitter, sour and sweet taste qualities. With thisarrangement, we demonstrate that

classify subjects as PROP non-tasters, moderate tasters, orsupertasters. The classification of PROP tasters was determinedby comparing PROP taste intensity to edible taste strips thatcontained 140 nmoles of NaCl. Next, taste recognition thresholdsfor PROP were examined by the ascending limits method, and themethod of reversals. In our subject population (n = 100),approximately 80 percent of subjects could detect PROP as bitter.For PROP tasters, taste recognition thresholds spanned two logunits with an upper limit of 130 nmoles. These taste recognitionthresholds were over one order of magnitude lower than thosereported with aqueous tests. Subjects were then tested for theirability to detect PROP with their nasal passages occluded. Tasterecognition thresholds for half of the subject population wereidentical in both the absence and presence of nose clamps. Theremaining subjects detected PROP at the next higher or nextlower amount. Edible taste strip technology is a highly sensitiveand promising method for examining bitter taste function. Thesestrips readily identify taste blindness to PROP, and can identifymoderate tasters and supertasters. Future studies will correlatePROP taster status with genotype analysis of the TAS2R38 gene,and how the ability to detect PROP may affect overall bitter tastefunction.#P302 Poster session VII: Chemosensory Psychophysics IIB6 mice display confusion in behaviorally discriminatingbetween quinine and citric acidYada Treesukosol, Clare M Mathes, Alan C SpectorFlorida State University Tallahassee, FL, USAIn rodents, some taste-responsive neurons respond to bothquinine and acid stimuli. There is also evidence in the literaturesuggesting that, under certain circumstances, rodents display somedegree of difficulty in discriminating quinine and acidstimuli. Here, male C57BL/6J mice (n=10) were explicitly testedin a quinine vs. citric acid discrimination task. Water-restrictedmice were first trained in a two response-operant discriminationprocedure to lick a response spout upon sampling from an arrayof sucrose concentrations and to lick another response spout uponsampling from an array of citric acid concentrations. Correctresponses were reinforced with water and incorrect responseswere punished with a time-out. The mice were then tested fortheir ability to discriminate between other pairs of tastestimuli. Mice had severe difficulty discriminating citric acid fromquinine and 6-n-propylthiouracil (PROP) with performanceslightly, but significantly, above chance. In contrast, mice wereable to competently discriminate sucrose from citric acid, NaCl,quinine and PROP. In another experiment, mice that wereconditioned to avoid quinine by pairings with LiCl injections(n=8), subsequently suppressed licking responses to quinine andcitric acid and, to a lesser extent, NaCl, but not to sucrose in abrief-access test (25 min session, 5 s trials) relative to NaClinjectedcontrol animals (n=7). However, mice that wereconditioned to avoid citric acid significantly suppressedlicking only to that stimulus compared with controls(n=8/group). Collectively, the findings from these experimentssuggest that in mice, citric acid and quinine substantially sharechemosensory features making discrimination difficult butare not perceptually identical.#P303 Poster session VII: Chemosensory Psychophysics IINon synomymous SNPs in human tas1r1, tas1r3, mGluR1 andindividual taste sensitivity to glutamateMariam Raliou 1,2 , Anna Wiencis 2 , Anne-Marie Pillias 1 , AurorePlanchais 1 , Corinne Eloit 1,3 , Yves Boucher 4 , Didier Trotier 1 ,Jean-Pierre Montmayeur 2 , Annick Faurion 11NBS-NOPA, INRA Jouy-en-Josas, France, 2 CESG-CNRS Dijon,France, 3 Dept ORL Hôpital Lariboisière Paris, France, 4 FacultéDentaire, UFR Ondotologie Paris, FranceHuman subjects show different taste sensitivities to monosodiumglutamate (MSG), some of them being unable to detect thepresence of glutamate. Our objective was to study possiblerelationships between non-synonymous single nucleotidepolymorphisms (nsSNP) in human tas1r1, tas1r3, as well as otherputative receptor coding genes (mGluR4 and mGluR1), and thetaste sensitivity of each subject to glutamate. The sensitivity wasmeasured using a battery of tests to distinguish the effect ofsodium ions from the effect of glutamate ions in monosodiumglutamate. A total of 142 genetically unrelated Caucasian Frenchsubjects were considered: 27 non tasters to glutamate (specificageusia), 21 hypo-tasters and 94 tasters. Expression of tas1r1 andtas1r3 was tested on fungiform papillae by RT-PCR on a sampleof subjects from all groups. nsSNPs were determined by genomicDNA sequencing. The frequency of the mutations was comparedacross subject groups. All subjects, including those presenting aspecific ageusia for glutamate, expressed the candidateheterodimeric receptor Tas1R1-Tas1R3. Ten nsSNPs wereidentified in tas1r1 (n=3), tas1r3 (n=3) and mGluR1 (n=4) genes.mGluR4 only showed 3 silent SNPs. Two mutations -C329T intas1r1 and C2269T in tas1r3- were significantly more frequent innon tasters compared to tasters whereas G1114A in tas1r1 wasmore frequent in tasters. Other nsSNPs including T2977C inmGluR1 and more rare nsSNPs are also involved but, using thesethree genes, a part of the interindividual variance remainsunexplained. Some of the nsSNPs reported here can partly explainthe observed individual differences of sensitivity to glutamate andthe taste of glutamate may involve also other receptors than thoseconsidered here.#P304 Poster session VII: Chemosensory Psychophysics IIUnderstanding the Relationship Between Saltiness and UmamiChristopher T. Simons, Kelly AlbinGivaudan Flavors Corp., Science & Technology Cincinnati,OH, USANaCl and MSG evoke sensations that humans recognize as saltyand umami, respectively. However, sensorially the relationshipbetween salt and umami is complex as most foods contain bothNaCl and umami compounds and the prototypical umamistimulus, MSG, includes Na+. Herein we sought to determinehow perceived salt and umami intensities change as (A) NaCl isheld constant and MSG concentrations vary and (B) MSG is heldconstant and NaCl concentrations vary. In each experiment,panelists were asked to rank aqueous mixtures of NaCl and MSGat varying concentrations according to perceived saltiness and/orumami intensity. As expected in exp 1, increasing MSG whileholding the NaCl concentration constant resulted in greaterperceived umami intensity. Similarly, as MSG levels increased,perceived saltiness increased. In exp 2, adding salt to a constantlevel of MSG increased perceived saltiness but had no effect onP O S T E R SAbstracts | 121

umami intensity. To ascertain the mechanism by which MSGincreased perceived saltiness of NaCl solutions (see exp 1), NaCl-MSG mixtures were compared to NaCl only solutions matchedfor total Na+ concentration using a 2-AFC methodology. Whentest solutions (MSG+NaCl and NaCl only) contained eqimolarconcentrations of Na, observed saltiness enhancement by MSGwas eliminated. This suggests that Na+ from MSG is responsiblefor the perceived saltiness enhancement observed in exp 1. Finally,advances in flavor chemistry have identified Na-free compoundsthat evoke umami sensations (Na-FUs). In exp 4 we investigatedif perceived salt and umami intensities change if NaCl levels areheld constant and a Na-FU compound is added. Similar to exp 1,adding Na-FU to NaCl increased perceived umami sensationbut only marginally increased perceived saltiness at lowconcentration.#P305 Poster session VII: Chemosensory Psychophysics IIPerceptual variation in umami taste and polymorphismsin TAS1R taste receptor genesQing-Ying Chen 1 , Suzie Alarcon 1 , Anilet Tharp 1 , Tiffani A.Greene 2 , Joseph Rucker 2 , Paul A.S. Breslin 11Monell Chemical Senses Center Philadelphia, PA, USA, 2 IntegralMolecular Inc. Philadelphia, PA, USAThe TAS1R1 and TAS1R3 G-protein coupled receptors (GPCRs)are believed to function in combination as a heteromericglutamate taste receptor in humans. In this study, we firstcharacterized the general sensitivity to glutamate in a samplepopulation of 242 subjects using discrimination task andextensively tested a subset of ten subjects at extremes ofsensitivity. We followed these experiments by sequencing thecoding regions of the genomic TAS1R1 and TAS1R3 genes for aseparate set of 87 individuals who were tested repeatedly withmonopotassium glutamate solutions and asked to rate umami tasteon a general Labeled Magnitude Scale. We established that there isconsiderable variation in umami taste perception. A subset ofsubjects at the extremes of sensitivity was subsequently studied ina battery of psychophysical tests validated the observation. Ingenetic sequencing experiment we revealed that TAS1R3, theshared subunit of the TAS1R sweet and umami taste heteromerreceptors, contained more variations than did TAS1R1, contraryto earlier reports. We identified one rare nonsynonymous singlenucleotide polymorphism (SNP) and four synonymous SNPs inTAS1R3 that have not been previously reported. Statisticalanalysis showed that the rare ‘T’ allele of SNP R757C in TAS1R3led to a doubling of umami ratings of 25 mM MPG. Othersuggestive SNPs of TAS1R3 include the ‘A’ allele of A5T and the‘A’ allele of R247H, which both resulted in an almost doubling ofumami ratings of 200 mM MPG. In conclusion, there is reliableand valid variation in human umami taste from L-glutamate.Variations in perception of umami taste correlated with variationsin the human TAS1R3 gene. Thus, this receptor is likelycontributing to human umami taste perception.#P306 Poster session VII: Chemosensory Psychophysics IIMonosodium Glutamate Taste Recognition Thresholds arenot Affected by Modulation of Serotonin or NoradrenalineLevels in Healthy HumansLucy F Donaldson, Tom P Heath, Ben Feakins, Nathan Jones,Charlotte Kenyan, Shyamal Raichura, Emma Richardson, LeilaRooshenas, Vicoria Smith, Jan K MelicharUniversity of Bristol Bristol, United KingdomThis study was designed to determine the effect of alteringserotonin and noradrenaline levels on monosodium glutamate(MSG) taste recognition thresholds in humans. We havepreviously shown that manipulation of these neurotransmitterslowers taste thresholds of specific taste modalities (Heath et al2006). A preliminary tongue map for MSG taste was generated in34 healthy adults (6 male, 28 female, age range 19-71) to determinethe most sensitive area of the tongue for further testing. In afurther 26 adults (13 male, 13 female, age range 19-48) a series ofMSG and sodium chloride solutions were presented either to theback or the tip of the tongue in a pseudorandom order.Recognition thresholds were calculated from psychophysicalfunction curves before and 2 hours after a single acute dose ofeither paroxetine (serotonin selective reuptake inhibitor),reboxetine (noradrenaline reuptake inhibitor), caffeine (activeplacebo) or placebo (lactose) in a double blind cross-over design.MSG taste recognition thresholds were significantly lower at theback of the tongue compared to the tip (back 14±3mM, tip,60±13mM, p

al 2008. Increases in glucose sensitivity were induced by treatmentwith glucose, Na-cyclamate and MSG, but not by water oracesulfame-K. Treatment with MSG, glucose or fructose increasedsensitivity to MSG, while water and acesulfame-K did not, andNa-cyclamate decreased MSG sensitivity. Treatment with IMPincreased MSG sensitivity, and that increase was reversed byadding Na-cyclamate to the IMP treatment solution. IMPtreatment had no effect on glucose sensitivity, and adding IMP toa Na-cyclamate treatment solution did not reverse the increasedglucose sensitivity produced by Na-cyclamate. The overall datasupport a peripheral mechanism and a role for T1R3 in theinduction. KMG is supported by NSF Graduate Fellowship.We thank Bio 040 students for assistance.#P308 Poster session VII: Chemosensory Psychophysics IIThe Effect of Amiloride on the Taste Quality of Salty SolutionsKathryn Luley, Anilet Tharp, James Bernhardt, Paul A. S. BreslinMonell Chemical Senses Center Philadelphia, PA, USASalt perception in humans may be partially mediated by theactivation of the epithelial sodium channel (ENaC), a selectiveion channel present in taste buds. Amiloride, an ENaC channelblocker, has been shown to affect salt taste perception in rodents;however its effect on human taste is not fully understood.While amiloride does not block salt taste in humans, it mayaffect the quality. In this study we investigated individualdifferences in amiloride sensitivity in humans, in particular theeffect of amiloride on the taste quality of salt. Subjects were askedto rate the intensity and quality of salt solutions tasted with andwithout amiloride. Our results suggest an effect of amiloride onsome humans and may help to futher elucidate the role of ENaCin human salt taste.#P309 Poster session VII: Chemosensory Psychophysics IISynchronicity Judgement of Gustation and OlfactionTatsu Kobayakawa, Hideki Toda, Naomi GotowAdvanced Industrial Science and Technology (AIST)Tsukuba, JapanSynchronicity of gustation and olfaction in food intake seriouslywill affect recognition of food perception. The synchronicity,however, is rarely investigated for integration process of gustationand olfaction. In this study, therefore, we focused on thesynchronicity perception between gustation and olfaction. Weused taste stimulator which was able to present pure gustationwithout tactile stimuli, and the timing of taste stimuli to tip ofparticipants’ tongues was measured in real time by three opticalsensors. We also used olfactometer equivalent Burghart’s OM4,with original developed real time stimulus monitoring usingultrasonic sensor. We used vision stimuli using LED in controlcondition. The distribution of synchronicity for “olfaction andvision”, and “gustation and vision” was almost equivalent as“vision and audition”. These results mean the perceptionprocesses for olfaction and gustation have equivalent temporalresolution compared to visual perception. The distribution ofsynchronicity for “olfaction and gustation” was quite differentfrom others. In other words, the synchronicity distribution ofolfaction and gustation was found to be much broader thanothers. This result might imply that the relation between olfactionand gustation is much closer than that between other sensations.#P310 Poster session VII: Chemosensory Psychophysics IIThe Effect of pH on Arginine Enhancement of Salty TasteNelsa Estrella, Paul A. S. BreslinMonell Chemical Senses Center Philadelphia, PA, USAWe have previously shown that L-arginine enhances saltytaste. The mechanism for this remains unclear. In this study, inorder to help elucidate the phenomenon further, we s determinedthe effects of pH on L-arginine’s enhancement of salty taste inhumans. Subjects were presented with mixtures of L-arginine andNaCl solutions of different pHs and asked to rate perceivedsaltiness using a general labeled magnitude scale. We replicatedour previous findings and showed that L-arginine does enhancesalty taste of salts. We further show that manipulations of pHaffect L-arginine’s ability to do so.#P311 Poster session VII: Chemosensory Psychophysics IISynergistic responses to L-glutamine and IMP in brief accesspreference testing in C57BL miceBenjamin K. Eschle, Meghan C. Eddy, J. Tyler Van Backer,Eugene R. DelayDepartment of Biology & Vermont Chemical Senses Group,University of Vermont Burlington, VT, USASynergy between 5’-inosine monophosphate (IMP) andL-glutamate is a defining characteristic of umami taste. Molecularexpression studies have shown that IMP may also interactsynergistically with other L-amino acids and, in some cases,IMP was necessary for cellular activation by the amino acid.These data suggest that IMP-induced synergy may extend to thetastes of other L-amino acids. Synergy is revealed when theresponse to a binary mixture is greater than the sum of theresponses to the components of the mixture. We examinedbehavioral synergy between glutamine and IMP in C57BL mice.Mice were studied in a non-deprived state in a brief accesspreference test paradigm. Lick rates were used to measurepreferences for a range of concentrations of both glutamine(10, 30, 100, and 200 mM) and IMP (0.3, 1, 3, and 10 mM) alone,as well as 16 binary combinations of the two. A predicted valuefor each of the binary mixtures was generated by summingthe lick rates for each the components presented along. Thesepredicted values are what would be expected in the absence of anysynergistic interaction. Actual lick rates to the mixtures werecompared to the predicted values to determine whether or notsynergy was present. Synergy was observed in mixtures withconcentrations of glutamine 30 mM and higher, and IMP 3 mMand higher. Testing will be continued with T1R3 KO mice toexamine what, if any, effect the absence of this receptor has onsynergistic interactions between L-glutamine and IMP.P O S T E R SAbstracts | 123

#P312 Poster session VII: Chemosensory Psychophysics IITaste Recognition Thresholds for Human SweetTaste FunctionSahbina A. Ebba 1 , Bradford Speck 1 , Lloyd Hastings 2 ,Gregory Smutzer 1,31Biology Department, Temple University Philadelphia, PA, USA,2Osmic Enterprises, Inc. Cincinnati, OH, USA, 3 Smell & TasteCenter, University of Pennsylvania School of MedicinePhiladelphia, PA, USAEdible taste strips composed of pullulan-hydroxypropylmethylcellulose polymers allow the delivery of precise amounts oftastants to the oral cavity. Edible taste strips are being used toidentify norms for human sweet taste perception as a function ofage in decades and sex. Taste recognition thresholds for sucrosewere examined by the ascending limits method and by the methodof reversals. Both approaches yielded nearly identical tasterecognition thresholds for sucrose. With edible strips, tasterecognition thresholds for sucrose ranged from 0.8 to 7.8micromoles (n = 60). The variability in thresholds wasconsiderably smaller with edible taste strips than with the use ofsolutions to deliver tastants. Overall, taste recognition thresholdsfor sucrose increased with subject age, and recognition thresholdswere similar for both males and females. Taste recognitionthresholds were also identified for the artificial sweetenersucralose. When sucralose was incorporated into edible strips,taste recognition thresholds averaged 4.9 nanomoles (n = 30),which was approximately 700 times lower than the average tasterecognition threshold for sucrose. Lactisole (sodium 2-(4-methoxyphenoxy) propanoate) is a compound that inhibits sweettaste perception in humans. An oral rise with a 0.23 millimolarsolution of lactisole failed to block the sweet taste of sucralosewhen this tastant was incorporated into taste strips, and presentedto subjects. Our threshold values for sucrose and sucralose arenearly two orders of magnitude lower when compared to resultsobtained from traditional aqueous taste tests. These resultsindicate that edible taste strips are a highly sensitive method forexamining sweet taste function in humans.#P313 Poster session VII: Chemosensory Psychophysics IISweetness Resists Suppression in Complex MixturesJuyun Lim 1 , Floor Oosterhoff 2 , Barry Green 2, 31Oregon State University Corvallis, OR, USA, 2 The John B. PierceLaboratory New Haven, CT, USA, 3 Yale School of MedicineNew Haven, CT, USALittle is known about the suppression of individual taste qualitiesin complex mixtures. The present study investigated tastesuppression in all possible binary, ternary and quaternarymixtures of sucrose (0.56M), NaCl (0.32M), citric acid (10mM)and QSO 4 (0.18mM). In exp 1, aqueous solutions were warmed ina 37°C water bath and presented in 5-ml samples in a sip-and-spitprocedure. On each trial Ss sequentially rated sweetness, sourness,saltiness, bitterness and ‘other’ using the gLMS. The resultsshowed that although all taste qualities exhibited suppression,sweetness was more resistant to suppression than the other tastequalities. Sweetness was not significantly suppressed in any binarymixture, and in quaternary mixture it was reduced by just 58%compared to 87%, 82% and 78% for the tastes of QSO 4, NaCland citric acid, respectively. In addition, it was found thatsuppression in ternary and quaternary mixtures was drivenprimarily by specific taste-quality interactions, e.g., sucrosealone suppressed NaCl saltiness by 83%. The unexpected findingthat sweetness was less vulnerable to suppression than other tastesled to a second experiment to rule out the possibility that thisfinding was an artifact of rating sweetness first on every trial, orfrom the use of 37°C solutions rather than typical roomtemperature solutions. The results confirmed the findings of exp.1 and found no significant effect of solution temperature or theorder of taste quality ratings. From a functional standpoint, theresistance of sucrose sweetness to suppression may be importantfor motivating the consumption of foods that are rich incarbohydrates. From a practical standpoint, the pronouncedsuppression of saltiness by sucrose may explain why the highsalt content of some processed foods goes undetected.#P314 Poster session VII: Chemosensory Psychophysics IISucroseoctaacetate aversion: preliminary evaluation of MSMconsomic mouse strains for gene-mappingDavid A Blizard 1 , Tsuyoshi Koide 2 , Toshihiko Shiroishi 2 ,Thomas P Hettinger 3 , Marion E Frank 3 , Ayako Ishii 21Pennsylvania State University University Park, PA, USA,2National Instituteof Genetics Mishima, Japan, 3 University ofConnecticut Health Center Farmington, CT, USAFor several decades, it had been assumed that aversion for thebitter tastant sucroseoctacetate (SOA) was under the control of asingle gene on mouse chromosome (Chr) 6. However, a recentQTL study reported that additional variants on mouse Chr 2, 11and 19 also influenced aversion for either 0.1 mM or 1 mMconcentrations of SOA in a cross of C57BL/6By and NZB/BINJstrains (Le Roy, Pager and Roubertoux, 1999). The creation of anew set of consomic strains by transferring M. m. molossinusgenetic material from the MSM wild-derived strain onto aC57BL/6 background presented the opportunity to screen forvariants that affect SOA aversion. A preliminary screen of malemice (N =5-10 per group) of C57BL/6 (B6: the host strain) andMSM (the donor strain) and 6 consomic strains was carried outusing 48 h 2-bottle tests in which water was paired with either 0.1mM or 1 mM SOA and preference/aversion ratios calculated.MSM strongly (aversion ratio ~10%) and B6 weakly (~30%)avoided both concentrations of SOA. No consomic strain avoided0.1 mM SOA but two (B6-6CMSM and B6-2CMSM) containing,respectively, chromosomal inserts from Chr 6 and Chr 2 avoided1 mM SOA (aversion ~10%). These findings confirm thatSOA aversion is determined by more than one gene in themouse. Completion of a screen of all of the MSM consomicstrains may unearth more variants that influence SOAaversion. The tools available for leveraging MSM/B6 comparisons(e.g. congenic strains, availability of genomic sequence) make theMSM/B6 model system an attractive resource for gene/gustationinvestigations. Reference Le Roy I, Pager J, Roubertoux PL.(1999) Genetic dissection of gustatory sensitivity to bitterness(sucrose octaacetate) in mice. C R Acad Sci III. 322(10):831-6.124 | AChemS Abstracts 2009

#P315 Poster session VII: Chemosensory Psychophysics IIMeasurements of stimulus preference vs. stimulus pleasantnessgive rise to different optimally liked concentrations of sucroseKristin J Rudenga 1 , Wambura Fobbs 1 , Dana M Small 1, 21Yale University New Haven, CT, USA, 2 John B PierceLaboratory New Haven, CT, USAThe pleasantness of a sweet taste has been described as a singlepeakedfunction that increases with intensity up to an optimallyliked concentration and then declines (Moskowitz et al. 1975 andothers). Pepino and Menella (2007) used a 2-alternative forcedchoice test (2-AFC) to show that subjects with a family history ofalcoholism prefer higher sucrose concentrations than thosewithout. The goal of the current study was to determine if the 2-AFC test identifies the same concentration of sucrose as thepsychohedonic curve (PHC). 29 healthy subjects were recruitedand their optimally liked concentration of sucrose was determinedby the 2-AFC and the PHC (conducted on separate days andcounterbalanced). The PHC was generated by asking subjects torate the intensity (using the gLMS) and pleasantness (using theVAS) of repeated presentations of 0.09, 0.18, 0.32, 0.56, and 1.00Msucrose. The 2-AFC consisted of subjects choosing their preferredsample from a pair of sucrose solutions of different strengths(selected from 0.09, 0.18, 0.32, 0.56, 0.70, and 1.00M sucrose). Thisidentifies the concentration that is preferred more than thoseimmediately weaker or stronger. We found that the 2-AFC andPHC identify different concentrations of sucrose as maximallyliked (PHC =0.70; 2-AFC =0.62; r 2 =0.096]. Moreover, theconcentration determined by 2-AFC, but not the concentrationdetermined by the PHC, was significantly correlated negativelywith a subject’s BMI and positively with alcohol use. Thissuggests that PHC and 2-AFC methods measure differentprocesses. Future work is needed to determine the nature of thedifference but an intriguing possibility is that judging pleasantnessvs. making a choice about preference represent differentdimensions of taste hedonics. Supported by RO1 DC006706.#P316 Poster session VII: Chemosensory Psychophysics IITaste damage associated with otitis mediaLinda M. Bartoshuk 1 , Frank A. Catalanotto 1 , Valerie B. Duffy 2 ,Miriam Grushka 1 , Vicki D. Mayo 1 , Monica C. Skarulis 3 ,Derek J. Snyder 1,41University of Florida Center for Smell and Taste Gainesville, FL,USA, 2 University of Connecticut Storrs, CT, USA, 3 NationalInstitutes of Health Bethesda, MD, USA, 4 Yale UniversityNew Haven, CT, USAA history of otitis media (middle ear infection) is associated withenhanced liking for energy dense foods and higher body massindex (Snyder et al, 2008). Since the chorda tympani (CN VII,taste, anterior tongue) passes through the middle ear on its way tothe brain, it is vulnerable to damage from otitis media. We confirmthis damage with a dataset (N=736) of spatial taste tests done for avariety of studies. NaCl, sucrose, citric acid and quinine wereswabbed on loci innervated by the chorda tympani andglossopharyngeal (CN IX) nerves; whole mouth taste was alsotested. Two psychophysical scales were used, both designed toprovide valid comparisons across subjects/groups. The first variedfrom 0-100 where 0=no sensation and 100=the most intensesensation of any kind imaginable. For the second, 100=the mostintense sensation of any kind ever experienced. The change inlabels reflects data showing that “imaginable” offers noadvantages and can produce confusion in some subjects.Both scales showed significant losses for bitter on the anteriortongue (chorda tympani) but not the posterior tongue(glossopharyngeal). Whole mouth taste intensities were notreduced; in fact, taste intensities for some stimuli were intensified.This provides support for our hypothesis that inhibitoryconnections among taste nerve projection sites in the brain resultin release of inhibition when one nerve is damaged. Thus,paradoxically, localized taste damage can intensify whole mouthtaste. Localized taste damage can also intensify non-tastesensations like the tactile sensations evoked by high fat foods(see Catalanotto poster). We suggest that these sensory/hedonicchanges lead to the weight gain observed in individuals withhistories of otitis media.#P317 Poster session VII: Chemosensory Psychophysics IIOtitis Media and intensification of non-taste oral sensationsFrank A Catalanotto 1,2 , Eric T Broe 1 , Linda M Bartoshuk 1,2 ,Vicki D Mayo 1,2 , Derek J Snyder 1,21University of Florida College of Dentistry, Department ofCommunity Dentistry and Behavioral Science Gainesville, FL,USA, 2 Center for Smell and Taste Gainesville, FL, USAA history of otitis media (OM) is associated with enhanced likingfor energy dense foods and higher body mass index (Snyder et al,2008). The chorda tympani nerve (CN VII, carries taste from theanterior tongue) passes through the middle ear on its way to thebrain; thus it is vulnerable to damage from OM. Paradoxically,localized damage can intensify whole mouth taste (see evidence atthe Bartoshuk poster) because of inhibitory connections betweentaste nerve projection sites in the brain (Catalanotto et al, 1993).Evidence also suggests that central inhibitory connections existbetween taste and oral pain leading to an association betweenintensified oral pain and OM (Bartoshuk et al, AChems 2007).Similarly, damage to the glossopharyngeal taste nerve (CN IX)has recently been associated with increased oral pain (Logan et al,2008). The present study was conducted to test another non-tasteoral sensation: tactile sensations evoked by fats. Subjects rated thethickness of 5 dairy products: nonfat milk, whole milk, half&half,heavy cream, heavy cream+oil on a scale from 0 to 100 where0=no sensation and 100=strongest sensation of any kind everexperienced. ANOVA with follow-up t-tests were conducted forsubjects with no history of OM vs those with histories of OM.The 2 groups were not significantly different for nonfat milk;subjects with histories of OM rated 3 of the 4 stimuli containingfat as significantly “thicker” than did those without this history(the difference for half&half did not reach statistical significancebut was in the same direction). We suggest that oral thickness is acue for energy density; this cue is likely to be associated with foodliking through conditioning. Intensification of this cue wouldpresumably be associated with even greater food liking leading toweight gain.P O S T E R SAbstracts | 125

#P318 Poster session VII: Chemosensory Psychophysics IIOral irritation elicited by menthol and cinnamaldehyde (CA):self- and cross-desensitizationE. Carstens, Mirela Iodi Carstens, Karen ZanottoUniversity of California, Davis Davis, CA, USAMenthol and CA are used in oral hygiene products for theirrefreshing sensory properties, but are irritating at higherconcentrations. We investigated if they exhibit self- and crossdesensitizationof their oral irritancy. Using a 2-alternativeforced-choice (2-AFC) paradigm, either menthol (19.2 , 28.8 mM)or CA (15.2, 30.4 mM) was briefly applied by filter paper to oneside of the dorsal tongue, with vehicle similarly applied to theother side. Following variable intervals, either menthol or CAwas applied bilaterally and subjects stated on which side theyexperienced greater irritation, followed by ratings of irritantintensity on each side using a labeled magnitudescale. Desensitization was manifest by a significant proportion ofsubjects choosing the vehicle-treated side as having strongerirritation, and assigning significantly higher ratings to that side.Menthol 19.2 mM exhibited significant self-desensitization andcross-desensitized irritation elicited by 15.2 mM CA applied 5but not 30 min later. CA 30.4 mM (but not 15.2 mM) crossdesensitizedirritation evoked by 28.8 mM menthol applied 5 and30 min later, and exhibited self-desensitization. These data areconsistent with self- and mutual cross-desensitization of mentholand CA-evoked responses of neurons in superficial layers oftrigeminal subnucleus caudalis. Using calcium imaging of culturedrat trigeminal ganglion neurons, we observed CA suppression ofmenthol-evoked responses, suggesting a peripheral site ofinteraction of these compounds on trigeminal nerve endings.#P319 Poster session VII: Chemosensory Psychophysics IIEvidence that repeated threshold testing can alter the perceivedintensity of tasteBarry Green 1,2 , Juyun Lim 31The John B. Pierce Laboratory New Haven, CT, USA,2Dept. of Surgery (Otolaryngology), Yale University School ofMedicine New Haven, CT, USA, 3 Dept. of Food Science andTechnology, Oregon State University Corvallis, OR, USAContext effects in taste have generally been attributed to responsebiases rather than to sensory mechanisms intrinsic to tasteperception. Here we report evidence that extensive exposure tothreshold-level tastes appears to heighten the perception ofsuprathreshold tastes. We discovered the effect in a study ofindividual differences in threshold and suprathreshold sensitivityto sucrose and NaCl that involved measurement of 6, 2AFCdetection thresholds over 3 sessions, followed by a 4 th session inwhich intensity ratings were obtained for 12 suprathresholdstimuli using the gLMS. Under these conditions intensity ratingswere 2-3 times higher than in a preceding experiment thatincluded some of the same stimuli but no detection task. Analysisof data from 7 Ss who participated in both experiments confirmedthe differences were statistically significant (p

differences in taste receptors is necessary for the study of foodand specific food preferences. The aim of this study was to screenthe hTAS2R38 taste receptor gene for variation in Finland (NorthEurope) and to compare the distribution of Finnish genotypes tothose of people in Philadelphia, PA. A total of 155 volunteeradults (114 females and 41 males) were recruited around SouthFinland (Fi), and in Philadelphia (Ph) a total of 75 subjects wererecruited (39 females and 35 males). All subjects were genotypedat three variable locations: AA 49, 262, 296 (Bufe et al, CurrentBiology 22: 322-327). A total of four alleles were observed in bothsamples. Ph was comprised of eight different diplotypes whereasFi was comprised of six. The PAV/AVI heterozygous subjectswere the predominant genotype group in both samples (37 %).The difference in “sensitive” PAV (Fi = 13 %, Ph = 24 %) and“insensitive” AVI (Fi = 39 %, Ph = 24 %) homozygous subjectgroups was significant between the samples. Our results indicatethe influence of wider gene pool on distribution and show theconservation of genes in isolated populations. As Ph has asignificant African American and African population segment,these data support the idea that genetic variation is maximizedwhen the population under study is heterogeneous and contains alarge portion of the population of African extraction.P O S T E R S#P322 Poster session VII: Chemosensory Psychophysics IIDevelopment of Multichannel Taste Stimulator SystemHideki Toda, Tatsu KobayakawaNational Institute of Advanced Industrial Science and TechnologyTsukuba, JapanIt is strongly required high performance taste stimulator that isable to present various kinds of tastants without any tactilestimulus for complicated psychophysical experiment, for example,taste detection or interaction between tastants or cross modalexperiment. Tastant, water, bubble were driven by positive airpressure in single channel type taste stimulator previouslyproposed. In this case, positive air pressure worked enough.It would be very difficult to present various tastats by addingparts into original one, because this addition leads instability.In this study, we develop a new negative pressure type gustatorystimulator system instead of previous proposed positive pressuretype for driving water and tastants. We can simplify wholemechanism of creating the gustatory stimulation compared withthe previous proposed system, especially, using siphon effect forcreating the gustatory stimulus section helps us improving thegustatory stimulus timing control stability. For example, oursystem can create 714 +- 8.7msec (mean +- S.D., N=60) gustatorystimulation if we set the gustatory width set to 700 msec. Inaddition, maximum pressure change of the mouth position is verysmall compared to detection threshold (264 Pa). Thiscontrollability of the gustatory stimulation will be useful forprecise analysis of the signal processing mechanism of tasteresponse in the field of (neuro-) physiology or humanpsychophysical study and apply for the study field of biologyor medical examination.Abstracts | 127

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IndexAbaffy, T - 48Abakah, R - P299Abe, K - P68, P192Abraham, M - P281Ache, B - P32, P160, P163, P171, P198Adams, C - P8Adler, J - P173Affourtit, J - 39Ahmed, O - P83Ahmed, S - P29Åhs, F - P284Akiba, Y - 62Alarcon, S - P300, P305, P321Albeanu, D - 51Albin, K - P304Albrecht, J - P110, P153, P263Albrecht, M - P119Alden, E - P14Amrein, H - 10Anderson, C - P145, P161Angely, C - P228Anholt, R - P123Antonelli, P - 7Aono, S - P125Appendino, G - P141Araneda, R - P217, P234Arevalo, N - P8Arrizabalaga, G - P26Arshamian, A - P278Artur, Y - P174Arzi, A - P155Asakura, T - P192Assadi-Porter, F - P139Atanasova, D - P288Audige, V - P296Bachmanov, A - P67, P74, P79, P184Baehr, W - P197Bahr, K - P77Bailie, J - P21, P210, P277Baird, J - P64, P212Bajec, M - 5Baker, H - 59, 62Bakos, S - P131Baly, C - P127Baquero, A - P177Bardy, C - 63Barkat-Defradas, M - P264Barlow, L - 2, P185Bartel, D - P36Bartoshuk, L - 7, P12, P57, P102, P138, P316,P317Bartoszek, I - 28Bartsch, P - P297Bassoli, A - P151Bath, K - P236Batram, C - P135Baum, M - 14Baumgart, S - P182Baur, A - P6Beasley, A - P238Beauchamp, G - 30, P63, P74, P100, P103,P184, P261Behrens, M - P141, P195Belloir, C - P190Beltran, F - P101Bennegger, W - P27Béno, N - P271Bensafi, M - P264Bernhardt, J - P300, P308Bilecen, D - P10Bitter, T - P51, P298Blacker, K - P252, P258Blake, C - P33Blizard, D - P314Bobkov, Y - P32Boesveldt, S - P18Bohbot, J - P99Bonnette, S - P251Bordey, A - 61Borgonovo, G - P151Bosak, N - P74Bose, S - 66Boucher, Y - P303Boughter, Jr., J - P73, P112Bourgeat, F - P264Bowman, N - P115Boylan, K - P285Boyle, J - P128, P140Boyle, S - P116Braak, H - P9Bradley, R - 25, P47, P230Brand, J - P63, P204Brann, J - P234Brasser, S - P76Brearton, M - P95, P210, P277Breer, H - P114Breslin, P - P52, P83, P142, P143, P300, P305,P308, P310, P321Breza, J - P178Briand, L - P149, P190Brockhoff, A - P141, P195Broe, E - P317Broome, D - P285Brückmann, H - P153, P263Brune, N - P195Brunert, D - P160, P171Brunjes, P - P105Bruno, L - P292Bryant, B - P296Buettner, A - P53Bugg, M - P238Bulsing, P - 56, P269Bult, J - P58Burgess, J - P60Burmeister, H - P51Buschhüter, D - P45, P117, P267Busquet, N - P239Byrd-Jacobs, C - P235Cahill, E - P207Caillol, M - P127Caimi, S - P151Cain, W - 6, P273Cameron, E - P268Cao, J - P204Cardozo, T - P183Carlisle, B - P21, P95Carlson, J - 71Carmean, V - P240Carr, K - 65Carr, V - P48Carstens, E - P318Carter, C - P86Cartoni, C - 4Cassell, J - P85Catalanotto, F - 7, P316, P317Cavallin, M - P78Cave, J - 62Chamero, P - 13Chang, A - 64Chaput, M - 50Chatelain, P - P120, P121Chaudhari, N - P147, P188, P194Chen, C - P148Chen, D - 58, P25, P152, P241Chen, J - P241Chen, Q - P305Chen, W - P237Cheng, S - P101Cherry, J - 14Chesler, A - P234Chevalier, J - P190Chien, M - 38Chintalapati, K - P98Chopra, A - P6, P51Chung-Davidson, Y - 65Cichy, A - P229Claudia, B - P195Cleland, T - 17, 53, P159Coates, L - P172Cockerham, R - P28Coleman, J - P75, P80Cometto-Muñiz, J - 6, P273, P281Congar, P - P127Contreras, R - P41, P44, P178Cooney, R - P82Coppola, D - P108, P228Corby, K - P15, P20Corey, E - P160, P163, P171, P198Corson, J - P37Costanzo, R - P131Coupland, J - P189Coureaud, G - P266, P271Cowart, B - P34, P49Crasta, O - P108Crawley, J - P11Croasdell, S - P177Croy, I - P4, P280Cruickshanks, K - P19, P102Culnan, D - P82Cygnar, K - P199D’Errico, F - P151D’Errico, G - P151Dacks, A - P113Dacks, J - P113Dalton, P - 57, P49, P257, P258, P259, P272Daly, K - P88, P89Damak, S - 4Dando, R - P179, P188Daniel, P - P86Bold indicates first/presenting authorAbstracts | 129

Dankulich-Nagrudny, L - P142Davidson, T - P23de Araujo, I - 8, P66de Wijk, R - P58Del Tredici, K - P9Delay, E - P311Delay, R - P124, P162Delvadia, N - P285Dennis, J - P125Derby, C - P93, P233Derjean, D - P29Desai, H - P301DeSimone, J - P75, P80, P186Desmetz, C - P190Dewis, M - P133Di Lorenzo, P - P43Dickens, J - P99Didier, A - 31Ding, S - P214Djordjevic, J - P2, P5, P128, P137, P270Donaldson, L - P306Dong, H - P214, P223Dooley, R - P182Dotson, C - P61, P62Doty, R - P268Doucette, W - P157Dougherty, D - 49Dovey, J - P282Dubuc, R - P29Duchamp-Viret, P - 50Dudai, Y - P154Dudgeon, S - P295Duffy, V - P55, P56, P138, P316Duke, F - P286Dunston, D - P130Durieux, D - P127Dvoryanchikov, G - P147, P194Dykstra, T - P176Ebba, S - P301, P312Ebnoether, M - P283Echeverri, F - P132Eddy, M - P311Egan, J - P62Eggleston, K - P250Egholm, M - 39Eguchi, A - 44Eichhorn, I - P153Eloit, C - P303Elson, A - P62Engelhardt, C - P175Enikolopov, A - P170Ennis, M - P107, P214, P223Erisir, A - 26, P37Escanilla, O - 31, P107Eschle, B - P311Estrella, N - P300, P310Etiévant, P - P271Fadool, D - P78Fakharzadeh, S - P3Faranda, A - P3Faurion, A - P303Feakins, B - P306Feng, P - P34, P143Ferreira, J - P66Fesl, G - P263Fields, H - 32Finger, T - P36, P196Finkbeiner, S - P59, P103Firestein, S - P118, P170, P234Flanagan, K - 13Fleischhacker, W - P7Fletcher, M - P237Fluegge, D - P175Fobbs, W - P315Fontanini, A - 36Forestell, C - P100Formaker, B - P98Frank, M - P98, P299, P314Frank, R - P21, P95, P210, P277Frasnelli, J - P128Frey, S - P1Fuhr, P - P10Fushiki, T - 44Galhardo, V - 8Gallagher, M - P3Gao, N - P132Gautam, S - P72Gelis, L - P167, P193Gelstein, S - 72Gerber, J - P13, P117, P267Gerstein, M - 39Gerwert, K - P167Gesteland, R - P277Gibaud, D - P266Gibson, N - P225Gieseke, J - P101Gilad, Y - 40Gilbertson, T - 3, 43, 45, P133, P177, P205Glaser, D - P63Glatt, A - P73Glendinning, J - P101Goldberg, D - P145Gonzalez, K - P307Goodman, A - P270Gordesky-Gold, B - P83Gordon, A - P14, P284Goto, T - P106Gotow, N - P309Gottfried, J - P104, P115, P126Gouadon, E - P127Gould, N - P242Gravina, S - P133Grebert, D - P127Green, B - P313, P319Green, E - P16, P17Green, W - P29Greene, M - P84Greene, T - P305Greer, C - 29, P245Griffith, J - P261Grigg, L - P212Grimes, T - P93Grindle, C - P259Grueschow, M - P104Grushka, M - P316Gu, W - P287Gudziol, H - P51, P298Gudziol, V - P45Gumucio, D - P276Guthrie, K - P220Haase, L - P16, P17Hadawar, H - 3Haddad, R - P168Haegler, K - P153, P263Hagelin, J - P211Hagendorf, S - 69, P175Hajnal, A - P82Hallock, R - P111Halpern, B - P253Hamilton, K - P222Hansen, A - P297Hansen, D - P205Hanson, K - P247Hanson, R - P172Hansson, B - 42, 70Harel, D - P122, P168Harkins, T - 39Harrington, H - P55Hartvig, D - P209Harvey, E - 2Hasin, Y - 39, P119, P286Hassenklöver, T - 28Hastings, L - P21, P262, P277, P312Hatfield, M - P88, P89Hatt, H - 67, P35, P167, P173, P182, P193,P198, P202, P227, P229Haupt, S - P96Häussinger, D - P224Hawkes, C - P9Hayes, J - P138Haynes, J - P104Hayoz, S - P129He, J - 11Heath, T - P306Hegg, C - P129, P206Heiser, C - P1Hellier, J - P8Henion, T - P187, P244Hennessy, S - P172Hermer-Vazquez, L - 37Hernandez, M - P14Herness, S - P165, P166Hersh, J - P259Hettinger, T - P98, P299, P314Hevezi, P - P132Heydel, J - P174Hill, D - 21, P42, P46, P295Hillier, K - P94Hiltbrand, C - P26Hinterhuber, H - P7Hirsch, A - P50Hirsh, S - P199Hivley, R - P166Hoffmann, H - P290Holman, P - P238Honda, H - P106Honeycutt, N - P117Hörmann, K - P1Hornung, D - P282Hoshino, N - P254Houpt, T - P85Howard, J - P104, P115, P126Howe, S - P210Huang, G - P19, P102Huang, Y - P146, P191Hummel, C - P6Hummel, T - P6, P10, P13, P18, P110, P224,P267, P278, P280, P283Hunker, R - P292Hutchins, M - P93Iannilli, E - P13, P51Bold indicates first/presenting author130 | AChemS Abstracts 2009

Illig, K - 19, P109Imoto, T - P136Inoue, K - 44Iodi Carstens, M - P318Irwin, M - P197Isamah, A - P3Ishii, A - P314Ishimaru, Y - P192Ito, A - P243Jaber, L - P166Jadauji, J - P137Jakob, I - P174Jancke, D - P35Jia, C - P206Jiang, J - P293Jiang, L - P77Jing, D - P236Johnson, B - P30Johnson, E - P84, P150Jones-Gotman, M - P128, P140Jones, N - P306Joraschky, P - P4Jordan-Sciutto, K - P24Jörg, S - P114Jorgensen, A - P26Jornlin, C - P259Junek, S - 28Jyotaki, M - P136, P164Kajiura, S - P97Kalabat, D - P132Kalwar, F - P88, P89Kamio, M - P93Kammerer, M - P224Kanekar, S - P232Kang, N - 14Kanzaki, R - P96Katagiri, H - 63Katare, Y - P90Katsevman, G - P254Katsumata, T - P80Kaur, A - 13Kawai, M - P134Kay, L - 18Keith, R - P285Kelahan, L - P290Kelliher, K - P26Kemmler, G - P7Kemmotsu, N - 9Kenemuth, J - P172Kenerson, M - P105Kennedy, K - P55Kennedy, L - P307Kenyan, C - P306Kereliuk, M - P90Kern, R - P48Keydar, I - P119Khan, R - P122Khen, M - P119Kim, D - 52, 64, P219Kim, F - P142Kim, J - P243Kim, P - 39Kim, S - 11Kinnamon, S - P145, P161Kishan Rao, S - P287Klasen, K - P163, P171, P198Kleemann, A - P153, P263Klein, B - P19, P102Klein, R - P19, P102Klimbacher, M - P7Klock, C - P49Klyuchnikova, M - P91Knaapila, A - P260Knott, T - P244Kobayakawa, T - P309, P322Kobayashi, K - P106Koelliker, Y - P60Kohl, J - P290Koide, T - P314Kokrashvili, Z - P81, P180, P196Kolks, J - P291, P292Komatsu, Y - P265Kopietz, R - P110, P153Korbel, J - 39, P119Kording, K - P115Köster, E - P209Krantz, E - P19, P102Krauskopf, E - P71Kreitler, S - P274Krolewski, R - P208Kronberg, E - P247Krone, F - P280Krosnowski, K - P201Krueger, S - P13Krull, C - 22Kuebler, L - 70Kuhn, C - P135Kullman, L - P38Kunze, D - 27Kurahashi, T - P200Kurtanska, S - 28Kurtenbach, S - P173Kwak, J - P3, P272Laframboise, A - P90Laita, B - P132Lancet, D - 39, P119, P122, P286Langaee, T - P138Lange, K - P280Lansky, P - 50Lapid, H - P122Laska, M - P279Laskowski, A - P181Lätzel, M - P298Lavine, M - P26Lawhern, V - P41Le Berre, E - P266, P271Le Bon, A - P174le Coutre, J - 4Le Pichon, C - P234Le, A - P307Lechner, T - P7Lee, A - 68Lee, F - P236Lehmann, S - P259Lehrach, H - P119Leinders-Zufall, T - 69Lemon, C - P76Leon, M - P30Levy, E - P22Li, A - P77Li, C - P39, P40, P40Li, W - 55, 65, P63, P69, P207Li, X - P63Libants, S - 65Lim, J - P313, P319Lin, C - P74Lin, W - P130, P201Linn, J - P153, P263Linster, C - 17, 31, P107, P223Liu, F - 2Liu, H - P220, P265, P276Liu, P - 3, 45, P205Liu, S - P215Livdahl, T - P307Lledo, P - 63Logan, D - 13Logan, H - P12Lord, J - P212Lorig, T - P269Louie, J - P286Lowe, G - P216Lu, M - P132Lucero, M - P197, P232Luebbert, M - P202Luetje, C - 48, P169Lukasewycz, L - P261Luley, K - P300, P308Luna, V - P158Lundstrom, J - P14, P18, P110, P128,P137, P284Lundy, R - P38, P213Luo, W - P130Luo, Y - P252Ly, X - P247Lyall, V - P68, P75, P80, P186Ma, J - P216Ma, L - 11Ma, M - 68, P248Mackay, T - P123Maillet, E - P139, P183Maîtrepierre, E - P149Manabe, Y - 44Mandairon, N - 31Mandel, A - P52Mannea, E - P95, P210, P277Manzini, I - 28Marcucci, F - P118Margolskee, R - P65, P67, P81, P164, P180,P183, P196, P287Markley, J - P139Marks, D - P24Marks, L - P320Marshall, A - P71Martel, K - 14Martin, N - P260Marton, T - 13Mashukova, A - 67Masilamani, S - P80Mathes, C - P302Mathew, D - 71Matsumura, K - 30Matsumura, S - 44Matsunami, H - 38Matsuo, S - P192Matsuo, T - 41Mattes, R - 47Mattila, S - P321Maurer, L - 29Maute, C - P257, P258, P259, P272Max, M - P139, P183Mayo, V - P12, P316, P317Bold indicates first/presenting authorIndex | 131

McClenon, C - P203McClintock, T - 66McCluskey, L - P144McCombs, K - P251, P292McDermott, R - P257, P258McGinnis, M - P64McIntyre, J - 66McTavish, T - P218Medler, K - P181Meister, M - 51Melichar, J - P306Melone, P - P75, P80, P186Melville, K - P253Mendenhall, W - P12Mennella, J - P54, P59, P100, P103,P259, P261Menzel, S - P195Merdato, N - P201Meredith, M - P33Meredith, T - P97Meunier, N - P127Meyer, H - P173Meyerhof, W - P135, P141, P195Migliore, M - 64Millar, S - 2Miller, A - 29, P245Miller, C - P3Miller, E - P64Miller, M - P113, P190Minegishi, R - P96Minski, K - P56Misaka, T - P192Mishina, Y - P265Mistretta, C - 21, P265, P276Mitsuno, H - P96Miyamoto, T - 10Mobley, A - 29Møller, P - P209Montague, S - 71Monteiro, C - 8Montez, J - P133Montmayeur, J - P303Moreno, M - 31Morgan, C - P15, P20Mori, K - 30Morini, G - P151Morrison, E - P125Mosinger, B - P81, P196Moyer, B - P132Mueller, C - P289Mummalaneni, S - P75, P80, P186Munger, S - P28, P61, P62Muralidhar, A - P113Murata, Y - P164, P184Murovets, V - P67, P79Murphy, C - 9, P15, P16, P17, P20, P23Murray, K - 63Murthy, V - 51Naaman, R - P122Nachtigal, D - 33Nagai, T - P192Nai, Q - P214, P223Nakai, J - 11Nakamura, S - P136Nakamura, Y - P106, P106Nakatani, K - P96Napier, A - P92Navia, J - P253Bold indicates first/presenting authorNawroth, J - 64Nedderman, E - P189Neeb, C - P236Negoias, S - P13Neuhaus, E - 67, P167, P173, P182, P193Ng, B - P35Nguyen, H - P185Nguyen, K - 64Nguyen, L - P93Nichols, A - P169Nicolelis, M - 8, P186Nighorn, A - P113Nikonov, A - P41, P178Ninomiya, Y - 4, P106, P134, P136, P164, P183Nishimori, K - P194Nissant, A - 63Nixon, R - P22Norgren, R - P189Nosrat, C - P243, P287Nosrat, I - P287Novak, L - P207Novosat, T - P172Nunez-Parra, A - P217Nusnbaum, M - P93Obata, K - P164Ogiwara, Y - P134Ogura, T - P201Oka, H - 30Oland, L - 23, P225Oleksiak, M - P254Olender, T - 39, P119, P122Oliveira-Maia, A - 8, P186Olsson, M - P14Olsson, S - 70Ong, J - P30Oosterhoff, F - P313Opiekun, M - 30Oriolo, L - P286Osterloh, M - P193Overton, J - P78Ozdener, H - P3Ozdener, M - P34, P204, P258Pack, C - P137Packard, A - P231Pala, A - 64Panguluri, S - P213Pankow, J - P19Paolini, M - P153Papes, F - 13Park, I - P32Parkes, W - P259Patel, H - 52, 64, P219Patel, T - P69Pelletier, L - P183Pelz, T - P173Pepino, M - P59, P103Pereira, E - P188Pesenti, F - P2, P5Peterlin, Z - P170Peters, O - P89Pettit, D - P158Pezier, A - P163Phan, T - P75, P186Philippeau, M - P120, P121Phillips, M - 52, 64, P219Pickering, G - 5Pillias, A - P303Piper, D - P209Pittman, D - 46, P64, P70Plachez, C - P246Plailly, J - P104Planchais, A - P303Plank, K - P52Pointer, K - P21, P95Poirier, N - P190Polet, I - P58Ponissery Saidu, S - P124Pradeep, S - P285Prescott, J - P242Preti, G - P3, P272Pribitkin, E - P49, P252, P257Price, J - 20Principe, J - P32Pritchard, T - P189Ptito, A - P2, P5Puche, A - 60, P28, P221, P246Puschmann, S - P117, P267Quijada, J - P183Rasche, S - P173Rachid, A - P190Radek, J - P139Radtke, D - P202, P227, P229Raichura, S - P306Raineki, C - P238Rainer, H - P114Raliou, M - P303Rao, X - P77Rasche, S - P173Raudenbush, B - P251, P291, P292Rawal, S - P138Rawson, N - P34, P49, P142, P296Ray, A - P116Reddaway, R - P42Reed, D - P54, P119, P260, P286Reidy, B - P203Reilly, J - P259Reisert, J - P199Ren, X - P66Rennaker, R - P156Repicky, S - 48Restrepo, D - P8, P157, P218, P239,P240, P247Reyland, M - P185Rhyu, M - P68Richardson, E - P306Richardson, L - P64Richter, J - P237Rinck, F - P264Ringh, A - P279Ritter, G - P278Robinson, A - P48Rochlin, M - P254Rodriguez, E - P285Roe, P - P84, P150Rolls, E - 35Rooshenas, L - P306Roper, S - P146, P179, P188, P191Rosen, A - P43Rosen, D - P49, P257Rospars, J - 50Roth, Y - 72Rothermel, M - P35Rouby, C - P264Roudnitzky, N - P135Roullet, F - P11Rozenkranz, L - 72132 | AChemS Abstracts 2009

Rucker, J - P305Rudenga, K - P315Rupp, C - P7Rybalsky, K - P95, P210, P277Sacquet, J - 31Sakurai, T - P96, P192Salcedo, E - P247Salesse, R - P127Samson, K - P294Sandell, M - P321Sander, T - P278Sanematsu, K - P134, P136Saunders, C - P69Sautel, M - P127Scarmo, S - P55Schaal, B - P266Schäfer, R - 42Schaffer, J - P43Scheer, I - P278Scheibe, M - P255Schellong, J - P4Schemmer, K - P278Schild, D - 28Schmidt, A - P255Schmidt, M - 24, P233Schmidt, R - 6, P273Schneidman, E - P275Schoebel, N - P227, P229Scholz, A - P7Schöpf, V - P153Schoppa, N - P218Schredl, M - P288Schubert, C - P19, P102Schulze, S - P289Schuster, B - P289Schwarting, G - P187, P244Schwerdtfeger, U - P10Schwob, J - P131, P208, P231Sclafani, A - P65Scott, A - P90Sela, L - P275Seo, H - P278Sezutsu, H - P96Shabolina, A - P79Shah, B - 3, 45, P133, P205Shah, N - 15Shao, Z - P221Shatz, C - 1Shaw, H - P61Shepard, T - P320Shepherd, G - 52, 64, P77, P219Shi, J - P125Shi, L - P144Shigemura, N - P134, P136Shiotsuki, T - P96Shipley, M - 16, P215, P221Shirasu, M - P31Shiroishi, T - P314Shirosaki, S - P134Sholudko, A - P138Shum, E - P199Sicard, G - P174Sichtig, H - P43Sigoillot, M - P149Silie, P - P183Silver, W - P69, P84, P150Simon, J - P60Simon, S - 8, P186Bold indicates first/presenting authorSimons, C - P195, P304Sims, M - P243Sinclair, M - P147, P194Skarulis, M - P316Slack, J - P195Small, D - 33, 34, P315Smeets, M - 56, P269Smith, D - P40, P285Smith, J - P85Smith, K - P70Smith, V - P306Smith, W - P23Smith, Z - P74Smitka, M - P117, P267Smutzer, G - P301, P312Snyder, D - 7, P57, P102, P316, P317Snyder, M - 39Sobel, N - 72, P122, P154, P155, P168,P274, P275Sollars, S - P294Song, A - P68Sonnabend, C - P195Soto, H - P132Soucy, E - 51Spain, H - P101Speck, B - P312Spector, A - P302Spehr, J - 69, P193, P227, P229Spehr, M - 69, P175Spitzer, J - P53St. John, S - P71Stamm, M - P197Stamps, J - P57Stanley, E - P211Staubach Grosse, A - P276Staudacher, E - P89Stehr, J - P135Steinle, N - P61Steinmeyer, A - P259Stensmyr, M - 42Stephan, A - P199Stevens, V - P203Stewart, R - P203Stone, L - P145Stover, A - P251Stowers, L - 13Stratford, J - P44Stuck, B - P1, P288Sullivan, R - P238Sun, C - P46Suwabe, T - P47Tabuchi, M - P96Taha, M - P92Taha, S - 32Takeuchi, H - P200Tamura, T - P96Tashiro, T - 30Teeter, J - 65, P204Tepper, B - P60Tessler Lindau, S - P18Tharp, A - P300, P305, P308Theodorides, M - P74Thiebaud, N - P174Thirumangalathu, S - 2Thomas-Danguin, T - P266, P271Thompson, R - P92Tian, H - P248Tierney, K - P90Timmerman, B - P119Tizzano, M - P196Toda, H - P309, P322Tokita, K - P73, P112Tokumori, K - P106Tolbert, L - P225Tong, J - P66Tonosaki, K - P87Touhara, K - 12, P31Tran, T - P247Treesukosol, Y - P302Treloar, H - P245Tripathy, S - P89Trotier, D - P303Tsuzuki, S - 44Tucker, K - P78Turner, L - P212Uchino, K - P96Ueno, H - P164Ukhanov, K - P32, P160, P171Ungureanu, I - P195Urban, A - 39Vainius, A - P34, P49Valentine, M - P124Van Backer, J - P311van Dam, R - P93Van Houten, J - P124VanDeGrift, K - P21, P262Vandenbeuch, A - P161Veithen, A - P120, P121Veldhuizen, M - 33, P320Véloso Da Silva, S - P174Ventura, A - P54Verhagen, J - P72Vijayaraghavan, S - P196Villanueva, R - P235Vollmer, B - P263Voznessenskaya, V - P91Walch, T - P7Wallace, M - P138Walton, K - P276Wang, M - P230, P320Wang, Y - P24, P222Warscheid, B - P173Warskulat, U - P224Waters, R - P40Waterston, M - P137Wattendorf, E - P10Weiler, E - P27Weiss, J - 69Weissbrod, A - P275Weissler, K - P274Wekesa, K - P92Welge-Luessen, A - P10, P283Wesson, D - P22Westermann, B - P10Wetzel, C - P198, P202White, T - P250Whitesell, J - P157, P240Wicher, D - 42Wiencis, A - P303Wiesmann, M - P110, P153, P263Wilkerson, C - 65Wilkin, F - P120, P121Willhite, D - 52, 64, P219Wilson, D - 54, P22, P148, P156Wilson, T - P257, P258Winnig, M - P135Index | 133

Winters, K - P251Wise, P - P256Witt, M - P224Wöhr, M - P11Wolf, S - P167Wolfensberger, M - P283Wooding, S - P135Workman, V - 8Wright, C - P212Wright, M - P260Wright, T - P291, P292Wu, K - P126Wu, P - 2Wysocki, C - P3, P119, P256, P260, P286Xiang, B - P69Xu, F - P77Xu, H - P133Xu, J - P296Yaldiz, S - P93Yamazaki, K - 30Yanagawa, Y - P164Yang, C - P162Yang, M - P11Yang, Q - P40Yasumatsu, K - 4Yasuo, T - P164Yeckel, C - P66Yee, K - P34, P257Yeomans, M - P242Yeshurun, Y - 72, P154, P155Yoneda, T - 44Yongquan, Z - P114Yoshida, R - P134, P164Yoshiura, K - P106Yoshiura, T - P106Yu, R - 11Yu, T - 45, P133, P205Yuhas, D - P211Zanotto, K - P318Zatorre, R - P128Zeiske, E - P297Zernecke, R - P153, P263Zhang, C - P226, P249Zhang, H - P197, P226, P249Zhang, K - P25Zhang, M - P241Zhang, P - P162Zhang, W - P113, P193Zhang, X - P118Zhang, Y - P108Zhao, B - P183Zhao, F - P165, P166Zhao, H - P199Zhao, K - P49, P252, P256, P293Zhou, F - P214Zhou, S - P123Zhou, W - P25, P152, P241Zhu, G - P260Zhuang, H - 38Zielinski, B - P29, P90Zlotnik, A - P132Zoller, M - P132Zolotarev, V - P67, P79Zou, D - P118, P234Zufall, F - 69Zukerman, S - P65Bold indicates first/presenting author134 | AChemS Abstracts 2009

AChemS Abstracts 2009 | 135

AChemSAssociation for Chemoreception SciencesProgram at a GlanceRegistration3:30 pm to 8:00 pmRegistration7:00 am to 1:00 pm, 6:30 pm to 7:30 pmRegistration7:30 am to 1:00 pm, 6:30 pm to 7:30 pmwednesday, april 22 thursday, april 23 friday, april 248:00 am8:15 am8:30 am8:45 am9:00 am9:15 am9:30 am8:45 am10:00 am10:15 am10:30 am10:45 am11:00 am11:15 am11:30 am11:45 am12:00 pm12:15 pm12:30 pm12:45 pm1:00 pm1:15 pm1:30 pm1:45 pm2:00 pm2:15 pm2:30 pm2:45 pm3:00 pm3:15 pm3:30 pm3:45 pm4:00 pm4:15 pm4:30 pm4:45 pm5:00 pm5:15 pm5:30 pm5:45 pm6:00 pm6:15 pm6:30 pm6:45 pm7:00 pm7:15 pm7:30 pm7:45 pm8:00 pm8:15 pm8:30 pm8:45 pm9:00 pm9:15 pm9:30 pm9:45 pm10:00 pm10:15 pm10:30 pm10:45 pmWelcome Banquet(Ticketed Event)6:00 - 8:00 PMsouth BallroomOpening and Awards Ceremony8:00 - 9:00 PMsouth BallroomGivadaun Lecture9:00 - 10:00 PMsouth BallroomGustation8:00 - 10:00 AMSOuth BallroomBreak10:00 - 10:30 AMGendereffects onolfactoryprocessing10:30 AM - 12:30 PMSouth BallroomBreak2:10 - 2:25 PMWorkshop: NIH3:00 - 5:00 PMtropics RoomPresidentialSymposium:On beyondglomeruli7:00 - 9:05 PMsouth ballRoomPostersession I:Chemosensorydisorders,models andaging/Centralchemosensorycircuits8:00 AM - 12:30 PMNorth BallroomIndustrySymposium(Ticketed Event)1:00 - 4:00 PMsouth ballroomIndustryReception(Ticketed Event)4:15 - 6:00 PMthe BoathousePostersession II:Chemosensoryresponse to,and controlof, feeding/Neuroethology7:00 - 11:00 PMnorth ballroomDevelopmentand Plasticity:First CentralChemosensoryRelays8:00 - 10:30 AMSouth BALLROOMBreak10:30 - 11:00 AMPolak YoungInvestigatorAwardWinners11:00 AM - 12:30 PMSouth ballroomIFF SpecialLecture7:00 - 8:00 PMsouth ballroomBreak8:00 - 8:15 PMReciprocalinteractionsbetween primarytaste and olfactoryprocessingnetworks andhigher cognition8:15 - 10:15 PMsouth ballroomWorkshop: NIH3:00 - 4:00 PMflorida RoomPostersession III:Corticalchemosensoryprocessing/Receptorgenomics andmolecularbiology8:00 AM - 12:30 PMnorth ballroomAChemS Business Meeting12:45 - 2:45 PMsouth ballRoomChEMA Social5:00 - 7:00 PMtropics roomPostersession IV:Chemosensorytransductionandperireceptorevents7:00 - 11:00 PMnorth ballroom136 | ISOT/AChemS Program 2009

Registration7:30 am to 1:00 pm, 6:30 pm to 7:30 pmRegistration7:30 am to 11:00 amsaturday, april 25 sunday, april 26Functionalevolution ofchemosensoryreceptors8:00 - 10:05 AMSouth ballroomBreak10:05 - 10:30 AMMaking senseof fat taste10:30 AM - 12:30 PMSouth ballroomClinical Luncheon(Ticketed Event)12:45 - 2:45 PMthe keys roomWorkshop: Computationalproblems in sequential stagesof odor processing3:00 - 5:30 PMsouth ballroomFollow thehead, not onlythe nose:Top-down influenceson olfactoryperception7:00 - 9:05 PMsouth ballroomPostersession V:Chemosensorymemory/Central synapticphysiology/Neurogenesis8:00 AM - 12:30 PMnorth ballroomPostersession VI:ChemosensorydevelopmentandPsychophysics I7:00 - 11:00 PMnorth ballroomGABA in thedevelopingolfactory system:From generationto differentiation8:00 - 10:05 AMSouth ballroomBreak10:05 - 10:30 AMOlfactory and VomeronasalSystems10:30 AM - 12:30 PMSouth ballroomPostersession VII:ChemosensoryPsychophysics II8:00 AM - 12:30 PMnorth ballroom8:00 am8:15 am8:30 am8:45 am9:00 am9:15 am9:30 am8:45 am10:00 am10:15 am10:30 am10:45 am11:00 am11:15 am11:30 am11:45 am12:00 pm12:15 pm12:30 pm12:45 pm1:00 pm1:15 pm1:30 pm1:45 pm2:00 pm2:15 pm2:30 pm2:45 pm3:00 pm3:15 pm3:30 pm3:45 pm4:00 pm4:15 pm4:30 pm4:45 pm5:00 pm5:15 pm5:30 pm5:45 pm6:00 pm6:15 pm6:30 pm6:45 pm7:00 pm7:15 pm7:30 pm7:45 pm8:00 pm8:15 pm8:30 pm8:45 pm9:00 pm9:15 pm9:30 pm9:45 pm10:00 pm10:15 pm10:30 pm10:45 pmProgram at a Glance | 137

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See you next yearat ournew venue!Tradewinds Resort | St. Petersburg, FloridaAChemS 32nd Annual MeetingApril 21-25, 2010More space, more rooms, more fun!

We congratulate Dr. Carla Shatz for her significant contributionsto the understanding of neuronal circuitry regulation andplasticity, and thank her for her outstanding lecture.www.givaudan.com