Givaudan-Roure Lecture - Association for Chemoreception Sciences

More documents

Recommendations

Info

93 Poster [ ] Gustatory Processing ALCOHOL ACTIVATES A SUCROSE-RESPONSIVE GUSTATORY NEURAL PATHWAY Lemon C.H. 1, Brasser S.M. 1, Smith D.V. 1 1Dept. of Anatomy & Neurobiology, University of Tennessee Health Science Center, Memphis, TN A strong association exists between the intake of alcohol and sweettasting substances. The neural mechanisms underlying this relationship are unknown, although recent data suggest that gustatory factors are involved. Here, we explored the role of taste receptors and CNS circuits for sugar taste in the gustatory processing of ethanol. Taste responses to ethanol (3, 5, 10, 15, 25 and 40% v/v) and stimuli of different taste qualities (e.g., sucrose, NaCl, HCl and quinine-HCl) were recorded from neurons of the nucleus of the solitary tract in anesthetized rats prior to and following oral application of the sweet receptor blocker gurmarin. The magnitude of ethanol-evoked activity was compared between sucrose-responsive (S , n = 21) and -unresponsive (S , n = 20) 1 0 neurons and the central neural representation of ethanol taste was explored using multivariate analysis. Ethanol produced robust concentration-dependent responses in S neurons that were dramatically 1 larger than those in S cells (P's ≤ 0.02). Gurmarin treatment selectively 0 and similarly inhibited ethanol and sucrose responses (P's ≤ 0.01). Across-neuron patterns of response to ethanol were most similar to those evoked by sucrose (multiple r = +0.89), becoming increasingly more so as the ethanol concentration was raised. Results implicate taste receptors for sucrose as candidate receptors for ethanol and reveal that alcohol and sugar taste are represented similarly by activity in the CNS. These findings have important implications for the sensory and hedonic properties of alcohol. Supported by NIH DC005270 and DC00353. 94 Poster [ ] Gustatory Processing CHARACTERIZATION OF RAT ORBITOFRONTAL CORTICAL NEURONS DURING AD LIBITUM DRINKING OF LIQUID REWARDS. Gutierrez R. 1, Nicolelis M.A. 1, Simon S.A. 2 1Neurobiology, Duke University, Durham, NC; 2Anesthesiology, Duke University, Durham, NC In gustatory physiology, the orbitofrontal cortex (OFC) contains neurons that have roles in tongue movements, satiety, and other motivational outcomes involved in obtaining rewards. There is, however, a paucity of information regarding the nature of the OFC responses obtained from freely-moving rats licking to obtain a reward. To this end we have chronically implanted bundles of electrodes in rat OFC while they were free to drink from a sipper tube water or a sucrose solution. 172 single unit responses were characterized. A crosscorrelogram analysis between licking and neural activity revealed that 17% of the responses faithfully followed the licking frequency (~ 7 Hz). Of these oscillating neuronal responses, 24% responded either more actively or with a different morphology when drinking sucrose than water, probably reflecting the differential reward values of these stimuli. To obtain a better understanding of the neuronal activity involved in the initiation of a licking bout, peri-event histograms were constructed using the onset of the first lick after at least a 1 sec pause. Four other morphologically distinct types of responses were identified. Relative to the initiation of a drinking bout: two types began firing before (anticipatory), one type decreased firing and the other increased firing. In summary, five types of OFC neurons have been identified. Two, as expected, are related to the anticipation of a reward; others however are related to licking, and to the nature of the reward. Supported by NIH DC-01065. 24 95 Poster [ ] Olfactory CNS Physiology and Coding ONTOGENY OF SENSORY-EVOKED RESPONSES IN RAT AMYGDALA Wilson D.A. 1 1Department of Zoology, University of Oklahoma, Norman, OK The amygdala plays a critical role in emotion and memory. Recent work has suggested that adult reactions to emotional and/or stressful stimuli can be shaped by the effects of early experience on amygdala functional ontogeny. However, while ontogeny of amygdala neuron phenotype and neuroananatomy have been described, very few descriptions of amygdala physiology and function during the postnatal and adolescent period exist. As a first step toward understanding how early experiences shape amygdala function, the present study examined amygdala single-unit activity and responsiveness to sensory input during postnatal development. Single-unit and local field potential (LFP) activity were recorded in amygdala nuclei (primarily basolateral) of urethane-anesthetized, Long- Evans hooded rats. Rats were aged PN10 to adult (> PN70). Spontaneous activity, odor-evoked and footshock-evoked activity were determined for each cell using peri-stimulus time histograms. Spontaneous activity increased and evoked response latency decreased with age. While both odor-evoked and footshock-evoked responses could be observed at all ages, the temporal structure of these responses changed dramatically over the age range tested. Odor-evoked LFP's showed strong oscillations in the high beta band in adults, however the primary frequency of these oscillations shifted to lower ranges in younger animals toward the theta range at PN10. Given the hypothesized importance of temporal structure in stimulus encoding, these developmental changes may be indicative of a slow postnatal emergence of mature sensory processing by the rat amygdala, perhaps contributing to the sensitivity of this structure to early experiences. 96 Poster [ ] Olfactory CNS Physiology and Coding FACILITATION OF MAIN OLFACTORY INPUT TO THE MEDIAL AMYGDALA AND MEDIAL PREOPTIC AREA BY GONADOTROPIN-RELEASING HORMONE (GNRH). Blake C. 1, Westberry J. 1, Case G.R. 1, Meredith M. 1 1Neuroscience, Florida State University, Tallahassee, FL Sensory signals received during mating activate brain regions along the vomeronasal pathway and the medial preoptic area. These activated regions contain cell bodies and fibers of gonadotropin-releasing hormone (GnRH) neurons, suggesting a possible relationship between chemosensory input and GnRH. Chemosensory input can be detected by the vomeronasal organ and/or the main olfactory system. The consequences of vomeronasal organ removal (VNX) are most apparent in sexually naïve animals. Experienced, but not inexperienced, male hamsters can use main olfactory input to maintain mating after VNX, suggesting that with experience, neural circuits acquire the ability to use main olfactory information as the essential chemosensory input for mating. GnRH has also been shown to restore mating behavior in naïve VNX male hamsters. GnRH may facilitate transfer of olfactory information to the medial amygdala and medial preoptic area (MPOA) in naïve intact and VNX males. Electrical stimulation of the main olfactory bulb activates neurons in anterior and posterior medial amygdala and increases expression of FRAs (Fos-related antigens) protein. Initial experiments indicate an icv injection of GnRH into the lateral ventricle increases activation in medial amygdala and medial preoptic area. These experiments examine the effect of GnRH on chemosensory information transfer via the main olfactory pathway to these regions that are involved in mating behavior driven by either chemosensory pathway. Supported by DC-005813 from NIDCD.
97 Poster [ ] Olfactory CNS Physiology and Coding ODOR RESPONSES OF CEREBRAL LOBE NEURONS Nikonov A.A. 1, Caprio J. 1 1Biological Sciences, Louisiana State University, Baton Rouge, LA Functional information as to how odors are processed at more central neural levels than the olfactory bulb (OB) is fragmentary at best in mammals and nonexistent in teleosts. The long-term goal is to determine similarities and differences in how odor information arriving via the olfactory tracts is processed within the cerebral lobes (CL) of the channel catfish compared to that in the OB. Odor-responsive neurons were located in caudo-medial and lateral regions of the CL as predicted from previous forebrain anatomical investigations (Finger, 1975; Bass, 1981). Recordings were performed in vivo with metal-filled glass microelectrodes. Tested were bile salts (taurocholic and taurolithocholic acids) and amino acids (L-methionine and L-arginine), effective odor stimuli in channel catfish (Nikonov & Caprio, 2001). Sixty-four CL neurons responded to the odor stimulation; 45 were excited and 19 were suppressed (12 by amino acids and 7 by bile salts). Fifteen units located medially in the CL were excited by bile salts and were unresponsive to amino acids. Twenty-six of the 30 excitatory units located more laterally responded to 0.1-100µM amino acid; 4 additional units within this region along the OB midline responded to bile salts. The medial-lateral distinction between excitatory responses to bile salts and amino acids reflects a similar topographical organization within the OB. Ongoing experiments will determine if an odotopic map as observed in the OB (Nikonov and Caprio, 2001) exists or is altered within the CL and whether the response properties of CL neurons are different from those of OB neurons to the same odors. Supported by NSF IBN-0314970 and NIH DC-03792 98 Poster [ ] Olfactory CNS Physiology and Coding ODOR REPONSIVENESS OF THE OLFACTORY CORTEX AND RESIDUAL TYROSINE HYDROXYLASE ACTIVITY IN THE OLFACTORY BULB IN THE CNGA2 KNOCKOUT MOUSE Lin W. 1, Restrepo D. 1 1Cell and Developmental Biology, Neuroscience Program and Rocky Mountain Taste and Smell Center, University of Colorado Health Sciences Center, Denver, CO Mice deficient for subunit A2 of the cyclic nucleotide-gated (CNG) channel respond to select odorants (see Restrepo et al abstract in this meeting of AChemS). We examined the presence of alternate transduction pathways and the potential role of necklace glomeruli, which receive axons from neurons expressing the cGMP pathway (Juilfs et al 1997, PNAS 94:3388-95) and remain active in CNGA2 KO mice (Baker et al 1999, J Neurosci. 19:9313-21). Immunoreactivity to the cGMP-stimulated phosphodiesterase (PDE2), tyrosine hydroxylase (TH) and odor-induced Fos was used to visualize necklace glomeruli, levels of glomerular activity and activation respectively. We found that the TH expression in juxtaglomerular cells surrounding PDE2-positive necklace glomeruli is dependent on afferent input as unilateral naris occlusion dramatically reduced the TH expression in CNGA2 KO mice. Importantly, exposure CNGA2 KO mice to a mixture of putative pheromones (2-heptanone and 2, 5-dimethylpyrazine) increased odorevoked Fos induction in juxtaglomerular cells of some necklace and regular glomeruli. Further, we observed Fos expression in a substantially larger number of cells in both the anterior olfactory nucleus (AON) and piriform cortex in CNGA2 knockout mice compared to the same regions from mice exposed to fresh air. These experiments provide evidence for alternate transduction pathways in the main olfactory system in mice. This work was supported by NIH grants DC00566, DC04657, DC006070 (DR) and DC0043(WL). 25 99 Poster [ ] Olfactory CNS Physiology and Coding SYNAPTIC MECHANISMS CONTRIBUTING TO OLFACTORY CORTICAL ADAPTATION Best A.R. 1, Wilson D.A. 1 1Zoology, University of Oklahoma, Norman, OK Anterior piriform cortex (aPCX) neurons rapidly filter repetitive odor stimuli despite relatively maintained input from mitral cells. This cortical adaptation is correlated with short-term depression of afferent synapses, in vivo. The purpose of this study was to elucidate mechanisms underlying this non-associative plasticity using in vivo and in vitro preparations and to determine its role in cortical odor adaptation. We have previously described our in vitro stimulation results. In particular, we have discovered that the longer lasting portion (~120 s) of the in vitro short-term synaptic depression can be blocked pharmacologically. Following 50 s of simulated odor stimulation, either the metabotropic glutamate II/III antagonist CPPG (500 µM) or the βadrenergic receptor agonist isoproterenol (20 µM) can decrease the duration of synaptic depression. More recently we have discovered that, in vivo, both adaptation of odor responses in the β (15-35 Hz) spectral range and the associated synaptic depression following a 50 s exposure to a mixture of odorants can also be blocked by intracortical infusion of CPPG (2.5 mM). Currently, we are extending this work to behavioral habituation using heart rate orienting response habituation as a measure of cortical adaptation. Prior to adaptation of the heart rate orienting response, 3 µl of 2.5 mM CPPG or vehicle will be infused into aPCX bilaterally. Results from the behavioral paradigm will assist in clarifying the independent roles of receptor adaptation and cortical adaptation in behavioral habituation to odors. Funded by NICHD. 100 Slide [ ] Olfactory CNS Physiology and Coding RAPID ODOR CHANGE AND BRAIN ELECTRICAL ACTIVITY Lorig T.S. 1, Rigdon M. 1, Poor A. 1 1Washington and Lee University, Lexington, VA Some odors produce increased activity in areas of the brain often associated with language even though the task demands do not explicitly involve language. Visual and auditory stimuli which change rapidly tend to produce more left temporal lobe activity than stimuli that change slowly. If odor mixtures are transduced in such a way that each component produces high temporal overlap with the other components, this should effectively be construed as rapid stimulus change and lead to more left temporal lobe responses. To test this hypothesis, 10 undergraduate students served as subjects in a chemosensory event-related potential (CSERP) study. Three odors, phenethyl alcohol, vanillin, and citral were presented in binary pairs via a constant flow olfactometer and stimulus administration was triggered by subjects' inhalation. The stimuli were presented in two different ways. Given the members of the binary odor pair, A and B, one condition (Slow) required subjects to smell a sequence of A followed by B. Both A and B lasted 300 msec and were counterbalanced. In the Fast condition, the sequence was A,B,A,B where each stimulus lasted 150 msec and was counterbalanced. In both cases, each odor lasted a total of 300msec and the total stimulus administration lasted 600msec. CSERP data were collected from 80 scalp locations. Analysis revealed that brain activity differed between the two types of stimulus administration. Subsequent analysis with LORETA indicated that the left temporal lobe was more active in the Fast condition supporting the hypothesis that temporal overlap in odor mixtures leads to more left temporal lobe activity.
Page 1 and 2: 1 Givaudan-Roure Lecture [ ] Givaud
Page 3 and 4: 9 Slide [ ] Olfactory Bulb Physiolo
Page 5 and 6: 17 Poster [ ] Taste Hedonics & Psyc
Page 7 and 8: 25 Poster [ ] Taste Hedonics & Psyc
Page 9 and 10: 33 Poster [ ] Vomeronasal Organ CHE
Page 11 and 12: 41 Poster [ ] Vomeronasal Organ NEW
Page 13 and 14: 49 Poster [ ] Olfactory Transductio
Page 15 and 16: 57 Poster [ ] Olfaction: Animal Beh
Page 17 and 18: 65 Slide [ ] Trigeminal Chemorecept
Page 19 and 20: 73 Poster [ ] Salt and Sour Taste E
Page 21 and 22: 81 Poster [ ] Salt and Sour Taste C
Page 23: 89 Poster [ ] Gustatory Processing
Page 27 and 28: 105 Poster [ ] Unicellular Chemorec
Page 29 and 30: 113 Poster [ ] Clinical Evaluation
Page 31 and 32: 121 Poster [ ] Clinical Evaluation
Page 33 and 34: 128 Slide [ ] Odorant Receptors & T
Page 35 and 36: 136 Poster [ ] Olfactory Developmen
Page 37 and 38: 143 Poster [ ] Olfactory Developmen
Page 39 and 40: 151 Poster [ ] Odor Activation and
Page 41 and 42: 158 Poster [ ] Odor Activation and
Page 43 and 44: 166 Poster [ ] Environment and Huma
Page 45 and 46: 174 Poster [ ] Trigeminal Chemorece
Page 47 and 48: 181 Poster [ ] Functional Organizat
Page 49 and 50: 189 Slide [ ] Beidler Colloquium on
Page 51 and 52: 195 Symposium [ ] Olfaction and Neu
Page 53 and 54: 203 Slide [ ] Development of the Gu
Page 55 and 56: 211 Poster [ ] Bitter Taste FUNCTIO
Page 57 and 58: 219 Poster [ ] Olfactory Bulb: Codi
Page 59 and 60: 226 Poster [ ] Olfactory Bulb: Codi
Page 61 and 62: 234 Poster [ ] Social Odors and Beh
Page 63 and 64: 242 Poster [ ] Social Odors and Beh
Page 65 and 66: 250 Slide [ ] Olfactory Behavior &
Page 67 and 68: 257 Symposium [ ] Non-neuronal Cell
Page 69 and 70: 265 Slide [ ] Chemical Ecology LARV
Page 71 and 72: 273 Poster [ ] Accessory Olfactory
Page 73 and 74: 281 Poster [ ] Olfactory Sensory Ne
Page 75 and 76:
286 Poster [ ] Olfactory Sensory Ne
Page 77 and 78:
294 Poster [ ] Sweet Taste BEHAVIOR
Page 79 and 80:
302 Poster [ ] Taste Psychophysics
Page 81 and 82:
309 Slide [ ] Cortical Signal Proce
Page 83 and 84:
317 Poster [ ] Taste: Animal Behavi
Page 85 and 86:
324 Poster [ ] Taste: Peripheral Co
Page 87 and 88:
332 Slide [ ] Human Olfaction: Path
Page 89 and 90:
339 Poster [ ] Human Olfaction: Pat
Page 91 and 92:
346 Poster [ ] Olfactory Regenerati
Page 93 and 94:
352 Slide [ ] Odorant Receptors COM
Page 95 and 96:
360 Poster [ ] Odorant Receptors MO
Page 97 and 98:
367 Slide [ ] Taste Genetics and Ph
Page 99 and 100:
373 Slide [ ] Pheromones CHEMICAL C
Page 101 and 102:
380 Slide [ ] Olfactory Development
Page 103 and 104:
388 Poster [ ] Cell Biology of the
Page 105 and 106:
395 Poster [ ] Olfactory Bulb: Neur
Page 107 and 108:
402 Poster [ ] Olfactory Bulb: Neur
Page 109 and 110:
410 Poster [ ] Multimodal Integrati
Page 111 and 112:
418 Poster [ ] Taste: Umami POLYMOR
Page 113 and 114:
426 Poster [ ] Human Olfactory Perf
Page 115 and 116:
Abou, Elizabeth, 309 Abraham, Micha
Page 117 and 118:
Fadool, Debra, 34, 35, 64, 392, 393
Page 119 and 120:
Kim, K-O, 297 Kim, Un-kyung, 191, 3
Page 121 and 122:
Olsson, Mats J, 160, 277 Olsson, Sh
Page 123 and 124:
Tetsuya, Ookura, 12 Tharp, Anilet A
show all

Givaudan-Roure Lecture - Association for Chemoreception Sciences

Create successful ePaper yourself

Delete template?

Save as template?