Abstracts - Association for Chemoreception Sciences

#P203 POSTER SESSION IV:
CHEMICAL SIGNALING AND BEHAVIOR;
ANIMAL BEHAVIOR/PSYCHOPHYSICS;
CHEMOSENSATION AND METABOLISM;
VOMERONSASAL AND CHEMICAL
COMMUNICATION
#P204 POSTER SESSION IV:
CHEMICAL SIGNALING AND BEHAVIOR;
ANIMAL BEHAVIOR/PSYCHOPHYSICS;
CHEMOSENSATION AND METABOLISM;
VOMERONSASAL AND CHEMICAL
COMMUNICATION
The Temporal Structure of Odor Mixture Perception in Rats
Leslie M Kay 1,2 , Nisarg M Mehta 1 , Cinar Doruk 3
1
Institute for Mind and Biology, University of Chicago Chicago, IL,
USA, 2 Department of Psychology, University of Chicago Chicago, IL,
USA, 3 St. John’s College Annapolis, MD, USA
Temporal structure of odor mixtures is often overlooked, but
this is what gives many mixtures their complex percepts. This
structure can help us understand the puzzling qualities of odor
mixtures. There is not yet any theory that can predict whether a
mixture of 2 monomolecular odorants will smell like both odors
(elemental), like one more than the other (overshadowing), or
like neither (configural or synthetic). One feature that is often
overlooked in studies of mixture perception is the difference in
perceptual arrival time for the two odors. These delays have been
measured in humans, but implementing these sensitive perceptual
assays in rats is much more difficult. We have developed a task
that allows us to do this in rats, using a combined 2-alternative
choice - go/no-go paradigm. The results show that behavioral
response profiles to timing differences in binary mixtures are
specific to the odor pair and that the responses to positive and
negative delays are not symmetrical. For example, at zero delay
(only the natural processes producing delays) in a 1:1 mixture of
amyl acetate and anisole, anisole overshadows amyl acetate. As
anisole is moved earlier in time overshadowing becomes stronger.
In the negative direction, with amyl acetate preceding anisole, the
mixture enters a configural regime at -50ms to -200ms and then
takes on an elemental quality at -250ms. These results suggest
that in the temporal domain, elemental and configural responses
are close, with overshadowing responses occupying a separate
part of the temporal space. The properties of odorants, such
as sorptiveness and volatility, that may contribute to temporal
effects are discussed. Acknowledgements: Institute for Mind and
Biology Seed Grant (LK) Hodson Research Fellowship (CD)
The Fine Temporal Structure of the Rat Licking Pattern:
What Causes the Variability in the Interlick Intervals and
How is it Affected by the Drinking Solution?
Xiong B. Lin 1 , Dwight R. Pierce 2 , Kim E. Light 2 , Abdallah M. Hayar 1
1
University of Arkansas for Medical Sciences, Dept. of Neurobiology &
Developmental Sciences Little Rock, AR, USA, 2 University of
Arkansas for Medical Sciences, Dept. of Pharmaceutical Sciences
Little Rock, AR, USA
Licking is a repetitive behavior controlled by a central pattern
generator. Even though interlick intervals (ILI) within bursts
of licks are considered fairly regular, the conditions that affect
their variability are unknown. We analyzed the licking pattern
in rats that were licking water, 10% sucrose solution, or 10%
ethanol solution, in 90 min recording sessions after 4 h of water
deprivation. The histograms of ILIs indicate that licking typically
occurred at a preferred ILI of about ~135 ms with evidence of
bi- or multi-modal distributions due to occasional licking failures.
The longer the pause between bursts of licks (≥3 consecutive licks
with ILIs 4 sec, the ILI
was the shortest (~110 ms) at the beginning of the burst and then
it increased rapidly in the first few licks and slowly in subsequent
licks. The first ILI of a burst of licks was not significantly
different when licking any of the 3 solutions, but subsequent
licks exhibited a temporal pattern characteristic of each solution.
Moreover, rats licked the ethanol solution in shorter bursts and
the sucrose solution in longer bursts when compared to water.
Therefore, rats may rapidly identify the fluid and modify their
licking behavior by adjusting the temporal pattern of licks and
the number of licks/burst. The rapid deceleration in licking rate
in bursts of licks that occurred after >4 sec pause was due to an
increase from ~27 ms to ~56 ms in the tongue-spout contact
duration while the intercontact interval was only slightly changed
(80-90 ms). Therefore, the contact duration seems to be the major
factor that increases the variability in the ILIs, and could be
another means for the rat to adjust the amount of fluid ingested.
Acknowledgements: Grant P20 GM103425-09
POSTER PRESENTATIONS
Abstracts are printed as submitted by the author(s).
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