Abstracts - Association for Chemoreception Sciences

#P131 POSTER SESSION III:
TRIGEMINAL; HUMAN OLFACTORY
PSYCHOPHYSICS; TASTE PERIPHERY
Genetic Contribution to Binaral Rivalry
Kepu Chen, Bin Zhou, Guo Feng, Wen Zhou
Institute of Psychology, Chinese Academy of Sciences Beijing, China
When two odorants of different structure and smell are
simultaneously presented to the two nostrils, we experience
alternations in olfactory percepts, a recently discovered
phenomenon termed binaral rivalry. In an effort to further
characterize this phenomenon and its nature, we adopted the
twin method and tested monozygotic (MZ) twins (n = 73 pairs)
that are genetically identical and dizygotic (DZ) twins (n =
70 pairs) that share about half of their genes. The majority of
participants experienced binaral rivalry over a course of 20
samplings of eugenol and amyl acetate, one to each nostril.
Large variances are observed in the number and the magnitude
of their perceptual switches. Critically, such individual
differences are partially genetic. The correlations between MZ
twins for the two aforementioned indexes are both higher than
those between DZ twins. The best-fitting genetic models showed
that over 30% of the variances in binaral rivalry rate and binaral
rivalry magnitude, respectively, were accounted for by additive
genetic factors. Our study represents the first large sample study
of binaral rivalry. The findings demonstrate a reliable genetic
component of this phenomenon and suggest an innate rhythm of
olfactory perception.
#P132 POSTER SESSION III:
TRIGEMINAL; HUMAN OLFACTORY
PSYCHOPHYSICS; TASTE PERIPHERY
Olfactory Plasticity in Young Adults
Beverly J. Cowart 1 , Marcia L. Pelchat 1 , Johan N. Lundström 1,2,3 ,
Ryan Crawford 1 , Lydia Milbury 1 , Kathrin Ohla 1,4
1
Monell Chemical Senses Center Philadelphia, PA, USA, 2 Dept. of
Psychology, University of Pennsylvania Philadelphia, PA, USA,
3
Dept. of Clinical Neuroscience, Karolinska Institute Stockholm,
Sweden, 4 German Institute of Human Nutrition Potsdam-Rehbrücke
Nuthetal, Germany
There is considerable evidence that olfaction is, in many ways,
a “learned” sense, showing experience-induced plasticity in
both central circuits and peripheral receptors even in adulthood.
Although this has been demonstrated in humans, the focus
has been on single chemicals to which some individuals are
initially insensitive. We sought to explore (1) the possibility of
enhancing young adult sensitivity to complex odors, (2) the role
of cognitive engagement (active identification of exposed odors
vs. simple exposure), and (3) the extent of transfer of learning to
unexposed odors. For this, we obtained both odor thresholds and
olfactory event-related potentials (OERPs) from 40 young adults
in an attempt to assess the neuronal mechanisms of potential
behavioral changes. Thresholds for four exposed and two
unexposed complex odorants were obtained at baseline, 6 and
12 weeks; OERPs in response to two of the exposed and both
unexposed odorants were obtained at baseline and 12 weeks.
Our behavioral results suggest that intermittent odor exposure
in these circumstances does enhance threshold sensitivity and
that cognitive engagement may further enhance generalization
to unexposed odorants. Our electrophysiological results show
learning-dependent amplitude changes, particularly of the late
positive component. Taken together, these data provide further
support for the notion that repeated exposure augments olfactory
sensitivity and that cognitive mechanisms exert a significant
modulatory effect. Acknowledgements: Supported by the U.S.
Army Research Office, grant #W911NF-11-1-0087.
#P133 POSTER SESSION III:
TRIGEMINAL; HUMAN OLFACTORY
PSYCHOPHYSICS; TASTE PERIPHERY
Proton-Transfer-Reaction Mass Spectrometry
Melanie Y Denzer 1 , Jonathan Beauchamp 2 , David W Kern 3 , Stefan
Gailer 2 , Norbert Thuerauf 4 , Johannes Kornhuber 4 , Andrea Buettner 1,2
1
Department of Chemistry and Pharmacy, Emil Fischer Center,
University of Erlangen-Nuremberg Erlangen, Germany, 2 Department
of Sensory Analytics, Fraunhofer Institute for Process Engineering
and Packaging IVV Freising, Germany, 3 Department of Comparative
Human Development, Institute for Mind and Biology, University
of Chicago Chicago, IL, USA, 4 Department of Psychiatry and
Psychotherapy, University of Erlangen Erlangen, Germany
Since their introduction in the mid-1990s, Sniffin’ Sticks have
been used effectively by many otolaryngologists to assess
olfactory dysfunction in countless patients. Despite their
widespread use, however, there is currently a lack of data on
the actual odorant concentrations released from the tips of
these pens and whether these emitted concentrations scale
linearly in accordance with the odorant concentrations of the
pen set. The purpose of this study was to ascertain whether the
Sniffin’ Sticks’ presumed odorant release was concordant with
the concentration of the odorant solutions placed in the pens.
The commercially-available odour threshold test containing
n-butanol was chosen here for evaluation. The threshold set
contains concentrations (v/v) ranging from 4 % (pen no. 1)
to 1.2 ppm v
(pen no. 16), with stepwise 1:2 dilutions. We also
tested an additional custom-made pen containing 8 % n-butanol
(pen no. 0). The odorant concentration emanating from the tip
of each pen was measured directly via proton-transfer-reaction
mass spectrometry (PTR-MS), which is an on-line analytical tool
for detection and quantitation of volatile organic compounds
(VOCs) – including odorants – at trace concentrations. The pens
were also subjected to repeated use to ascertain the degree of
reproducibility of emitted odorant concentrations under stress.
These measurements showed that the concentration linearity of
n-butanol emitted over the range of pens was excellent and highly
reproducible. The stress tests demonstrated that the emitted
concentrations of n-butanol were lower after repeated use of the
pens compared to those of the unused pens, albeit with a mostly
good linearity over the entire range of pens. Acknowledgements:
Part of this study is affiliated with the Neurotrition Project,
which is supported by the FAU Emerging Fields Initiative. This
POSTER PRESENTATIONS
Abstracts are printed as submitted by the author(s).
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