1 1 Symposium Chemosensory Receptors Satellite DEVELOPMENT ...

133 Poster Chemosensory Coding and ClinicalRETRONASAL BUT NOT ORAL-CAVITY IDENTIFICATIONOF NON-TRIGEMINAL ODORANTSChen V. 1 , Halpern B.P. 2 1 Neurobiology & Behavior, CornellUniversity, Ithaca, NY; 2 Psychology and Neurobiology & Behavior,Cornell University, Ithaca, NYVapor-phase odorants may be stimuli for the olfactory system, thetrigeminal system, or both systems. Odorants known to have little or novapor-phase trigeminal component (e.g., Doty et al., Physiol. Behav.,20, 1978; Cometto-Muñiz et. al., Chem. Senses, 30, 2005) should beineffective when present in the oral cavity if retronasal olfactorystimulation is prevented. To study this, retronasal (retro) and oralcavity-only(trigem) identifications of 67% octane (O) and 10%coumarin (C), octanoic acid (OA), phenylethyl alcohol (PEA) andvanillin (V), delivered in vapor-phase and presented 3 times each inrandom order, were made by 20 non-smoking unscreened subjects (14females, median age = 20). RESULTS: Correct identifications (ID) forretro were significantly greater than trigem, p 0.12, two-tailed t-test) between ortho and retro, andmean final intensities were less than initial intensities. However, onlyortho intensity increased before decreasing. Mean ortho intensityincreased 10% between initial and maximum (p < 0.0001), with finalintensity 19% below initial (p < 0.0001). In contrast, mean maximumretro intensity was not significantly different from initial intensity (p =0.1324), but final retro intensity was 17% less than initial (p < 0.0001).Another difference was that mean absolute retro intensity was 20-22%less than ortho (p < 0.0001). CONCLUSIONS: Retro and orthosmelling have similar decreases in judged intensity over 90 sec,although ortho but not retro intensity increases before decreasing.Support from USDA Hatch NYC-191403.135 Poster Chemosensory Coding and ClinicalROUTE OF ADMINISTRATION ALTERS OLFACTORYPERCEPTIONSimons C.T. 1 , Webb L. 1 , Luzuriaga D.A. 1 , Burland M. 1 1 Research &Development, Givaudan Flavors, Cincinnati, OHOlfactory percepts appear to depend on the route by which odorantsreach olfactory receptors. Several studies have documented the inabilityof subjects to identify odorants retronasally (RN) that had previouslybeen identified when delivered orthonasally (ON). However, suchparadigms depend not only on subject´s inherent sensory acuity, butalso their odorant and semantic memory. To obviate the confoundinginfluence of memory associated with identification tasks, we presentlyused a matching methodology where subjects evaluated a flavor in onecondition (ON or RN delivery) and identified the same flavor from agroup of 5 unknowns evaluated in either the same or different deliverycondition. The delivery conditions included (a) ON delivery ofreferences and unknowns (b) RN delivery of references and unknownsand (c) RN delivery of references and ON delivery of unknowns. In exp1 subjects matched familiar flavors (orange, lemon, strawberry, pear &grape), in exp 2, unfamiliar flavors (lulo, acerola, guanabana, hibiscus& papaya) and in exp 3 strawberry flavors having different profiles(fruity, green, woody, ripe & candy). In all 3 exps, subjects correctlymatched significantly more flavors when the reference and unknownwere delivered via the same route (i.e., RN-RN or ON-ON) than whenreference and unknown were delivered via separate routes (RN-ON)supporting the hypothesis that the qualitative content of olfactorypercepts are route dependent. Moreover, performance decreased asflavor familiarity decreased and flavor similarity increased, suggestingthat specific cognitive strategies used in the matching task influencematching ability.136 Poster Chemosensory Coding and ClinicalCOMPARISON OF RESPONSES TO ELECTRICAL ANDCHEMICAL STIMULIStevens D.A. 1 , Cutroni E. 1 , Frey A.M. 1 , Lawless H.T. 2 1 Hiatt School ofPsychology, Clark University, Worcester, MA; 2 Food Science, CornellUniversity, Ithaca, NYPerceived qualities from electrical and chemical stimuli werecompared using physically similar stimulus delivery systems. Twentyfemale and 6 male young adult volunteers applied 1.6 v and 3 vbatteries, and stainless steel washers of equivalent area holding thefollowing tastants in approximately iso-intense quantities to the tips oftheir tongues for 1 sec: NaCl (applied twice to provide a measure ofreliability, which was high), citric acid, FeSO4, quinine HCl, alum,NaCl + citric acid, NaCl + quinine HCl, citric acid + quinine HCl. Theresulting sensations were rated on 14 attributes utilizing line scales.Analysis by rectangular multidimensional scaling (unfolding) produceda satisfactory 3-d solution (S-STRESS = 0.097; RSQ = 0.982). Thedimensions reflected tactile, saltiness, and hedonic qualities.Examination of the inter-point distances showed that the sensationsproduced by batteries were described best by the attributes `metallic,”“copper penny,” and “sharp,” and that the electrical stimuli werepositioned apart from the chemical stimuli and from their commondescriptors. Thus the perceived qualities of electric-metallic sensationsfrom the batteries differed from those of chemical stimuli, even whenthe two kinds of stimuli had similar tactile characteristics. The metallicquality perceived from electrical stimulation is consistent with previousliterature (e.g. Lawless et al., Chem. Senses, 2005, 30, 185-194).Supported by NIH RO1-DC-06223 to HTL.34