1 1 Symposium Chemosensory Receptors Satellite DEVELOPMENT ...

149 Slide Chemosensory Coding and ClinicalANALYSES OF HUMAN AXILLARY ODORS AND THEIRPRECURSORS IN NORMAL AND STRESSFUL SITUATIONSYabuki M. 1 , Takeuchi K. 1 , Hagura T. 1 , Hasegawa Y. 1 1 Tokyo ResearchLaboratory, Kao Corporation, Tokyo, JapanOur laboratory previously reported the 3-Hydroxy-3-methylhexanoicacid (3H3MH) and 3-methyl-3-sulfanylhexan-1-ol (3M3SH) as keyodorants in human axillary sweat (Hasegawa, 2004). We had alsoelucidated the occurrence of cysteine-linked precursor of 3M3SH on theaxillary skin and applied for a patent for the use of body odor indicator(Yabuki, 2004). One objective of this study is to analyze amino acidlinked axillary odor precursors quantitatively. A second objective is toevaluate the effect of mentally stressful situation on axillary odor. Inthis study, we evaluated axillary odor of healthy American women (n =26, aged 18-63) and collected their sweat samples in both normal (day1) and mentally stressful situation (day 2). During 10-minute stresssession trained moderator asked math, trivia and word questions tosubjects continuously. LC-MS/MS analyses showed there wascorrelation between the precursor levels on skin surface and odorintensity. Whereas the ratios of glutamine-linked two odor precursors,Gln-3H3MH to Gln-3M2H (3-Methyl-2-Hexenoic acid) wereapproximately 7:1 with no inter-subject variation, the ratios of Gln-3H3MH to Cys-3M3SH were unique to subjects. This finding indicatesa presence of common synthetic pathway for the glutamine-linked3H3MH and 3M2H. The temperature and other circumstances remainedunchanged for testing two days. However, 70% of subjects of the day 2had higher odor and precursor levels compared to day 1. Some subjectshad more than three times higher amounts of precursors. This resultsuggests mental stress induced perspiration acts as an accelerator forstrong odor formation.150 Poster Chemosensory Coding and ClinicalVOLATILE CONSTITUENTS OF HUMAN SKIN: GENETICFACTORS AND BIOCHEMICAL INDIVIDUALITYNovotny M.V. 1 , Soini H.A. 1 , Klouckova I. 1 , Wiesler D. 1 , OberzaucherE. 2 , Grammer K. 2 , Dixon S. 3 , Gong F. 3 , Brereton R. 3 , Penn D. 4 1 Institutefor Pheromone Research, Indiana University, Bloomington, IN; 2Anthropology, Ludwig-Boltzmann-Institute for Urban Ethology, Vienna,Austria; 3 Centre for Chemometrics, University of Bristol, Bristol,United Kingdom; 4 Konrad Lorenz Institute for Ethology, AustrianAcademy of Sciences, Vienna, AustriaHuman skin surface contains different types of glands that excretenumerous compounds, including polar and nonpolar lipids and peptides,but also small volatile organic compounds (VOCs) which can beolfactorily active. Human body odors can reflect physiological state andmood of individuals. Body odors appear to have their genetic attributes(e.g., MHC-related odors), while resident microflora can contribute totheir occurrence. The studies of VOCs in human emanations have beenlimited by the lack of quantitative techniques for comparing a largenumber of individuals. We have recently developed a high-throughputand highly quantitative technique for VOC profiling, which allowed tomonitor precisely about 400 compounds by gas chromatography/massspectrometry. Repeatedly collected VOC samples of 195 subjects wereanalyzed. Advanced chemometric methods were employed forevaluation of the VOC profiles. Numerous marker compoundsdistinguishing gender, families and individuals were located. Variousoxygenated compounds were identified as prominent markermetabolites. Their biochemical and genetic significance will bediscussed.151 Poster Chemosensory Coding and ClinicalPROBING THE CEREBELLAR ROLE IN SNIFFING WITHTRANSCRANIAL MAGNETIC STIMULATION (TMS)Mainland J. 1 , Ivry R.B. 1 , Sobel N. 1 1 Neuroscience, University ofCalifornia, Berkeley, Berkeley, CASniffs are modulated in response to odor concentration; higherconcentrations of odor induce lesser-volume sniffs. Studies usingfunctional magnetic resonance imaging (fMRI) and lesion patients bothsuggest a cerebellar role in this olfactomotor response. However, fMRIis a correlational technique and lesion patients may have developedcompensatory strategies that differ from healthy subjects. To probewhether cerebellar function is essential to the olfactomotor response inhealthy subjects, we will use transcranial magnetic stimulation. We firstset out to determine the relevant time-window for TMS application. Wefound that sniff volume was concentration-independent for the first 150ms, but inversely proportional to odorant concentration after 160 ms(t(8) = 3.12, p < 0.014). TMS has been shown to have a temporalresolution of 50 ms in visual tasks, suggesting that single-pulse TMScan probe the time course of cerebellar involvement in the olfactomotorresponse. To probe this time-course, single-pulse TMS will be appliedto the cerebellum at 100 ms preceding the start of the sniff, the start ofthe sniff, 100 ms after the start of the sniff and 200 ms after the start ofthe sniff. Influence of the TMS pulse on both sniffing and olfactoryperformance will be assessed.152 Slide Taste Chemoreception"FATTY"—A PRIMARY TASTEChalé-Rush A. 1 , Mattes R.D. 1 1 Foods and Nutrition, Purdue University,West Lafayette, INPreliminary psychophysical data indicate that long-chain fatty acidsof varying saturation are effective taste stimuli. This is consistent withelectrophysiological and animal data. The present study sought toisolate the taste property of three 18-C fatty acids by masking othersensory attributes. Linoleic, oleic, and stearic fatty acids were sonicatedin deionized water in concentrations ranging from 0.00028 % to 5%(w/v). To minimize oxidation, samples were stored under nitrogen.Stimuli were prepared fresh daily and 0.01% EDTA (w/v) was added toeach sample. The contribution of viscosity was minimized by additionof 5% Acacia (w/v) to the vehicle. Lubricity effects were reduced byaddition of 5% mineral oil (w/v). To determine if the effective stimuluswas an oxidation product, oxidized linoleic acid was included amongthe test stimuli. Testing was conducted with participants wearing noseclips and under red light to eliminate olfactory and visual cues.Detection thresholds were obtained using a three-alternative, forcedchoiceascending concentration presentation procedure. The criterionstopping rule was three consecutive correct identifications of a targetsample. Incorrect identification resulted with presentation of the nexthigher fatty acid concentration. The mean detection threshold forlinoleic was 0.11% (SD = 0.24), for oleic 0.02% (SD = 0.04), for stearic0.09% (SD = 0.21) and oxidized linoleic 0.05% (SD = 0.11). Theresults are indicative of a gustatory component to fat perception inhumans. Supported by NIH grant R01 DK45294-1438