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the olfactory experience on the spatial representation in the
olfactory bulb. Acknowledgements: Agence Nationale de la
Recherche ANR-09-JCJC-0117-01
#P110
POSTER SESSION III:
OLFACTION DEVELOPMENT & CNS;
HUMAN PSYCHOPHYSICS; TASTE PERIPHERY
Odorant Exposure Can Decorrelate Primary Odor
Representations and Improve Odor Discrimination in
Adult Mice
Marley D. Kass, Andrew H. Moberly, Stephanie A. Guang,
Michelle C. Rosenthal, John P. McGann
Rutgers University/Psychology Department
New Brunswick, NJ, USA
Adaptive plasticity can permit the optimization of sensory function
for a given environment. Last year we reported that chronic odorant
exposure substantially altered the pattern of synaptic input from
olfactory receptor neurons (ORNs) to olfactory bulb glomeruli
(Moberly et al. 2011,
AChemS P108
). Here we optically imaged
from the olfactory bulbs of mice that express the fluorescent
exocytosis indicator synaptopHluorin in ORN terminals (Bozza et
al. 2004) to compare patterns of ORN input between the
structurally similar odorants hexanal (HEX) and heptanal (HEPT)
before and after seven days of exposure to an unrelated odorant
(butyl acetate, BA). We found that the spatial patterns of HEX- and
HEPT-induced neural activity became decorrelated in BA-exposed
mice but not in home cage controls. We then tested for changes in
odorant discrimination abilities using a cross-habituation task (see
Mandairon et al 2006). During baseline testing wild-type mice did
not discriminate between HEX and HEPT, nor between (+)- and (-
)-limonene or pentanol and butanol. When tested again with the
same three odorant pairs after one week of exposure, BA-exposed
mice spontaneously discriminated between HEX and HEPT and
between (+)- and (-)-limonene, whereas home cage controls
continued to cross-habituate between odors. These data
demonstrate that exposure to a single odorant can enhance contrast
between primary olfactory representations of odorant pairs that are
chemically unrelated to the exposed odorant and that this
decorrelation can lead to a gain of olfactory function. Together,
the present findings also provide novel support to the conventional
model that odor quality is represented by the spatial pattern of
odorant-evoked ORN afferents. Acknowledgements: This work was
supported by grant R00 DC009442 from the National Institute on
Deafness and Other Communication Disorders to JPM
#P111
POSTER SESSION III:
OLFACTION DEVELOPMENT & CNS;
HUMAN PSYCHOPHYSICS; TASTE PERIPHERY
Odour Specificity and Response Characteristics of Bulbar
Neurons Linking Olfaction to Locomotion
Warren W. Green
1
, Cory L. Ochs
1
, Huiming Zhang
1
,
Weiming Li
2
, Réjean Dubuc
3,4
, Barbara S. Zielinski
1
1
Department of Biological Sciences, University of Windsor
Windsor, ON, Canada,
2
Department of Fisheries and Wildlife,
Michigan State University East Lansing, MI, USA,
3
Groupe de
Recherche sur le Système Nerveux Central, Département de
Physiologie, Université de Montréal Montréal, QC, Canada,
4
Département de Kinésiologie, Université du Québec à Montréal
Montréal, QC, Canada
The peripheral olfactory organ of the sea lamprey is comprised of
the main olfactory epithelium and an accessory olfactory organ.
Olfactory information from the main epithelium and accessory
organ transits through a uniglomerular medial region of the
olfactory bulb to command neurons in the hindbrain driving
locomotion; while non-medial regions of the olfactory bulb receive
olfactory information exclusively from the main olfactory
epithelium and primary output neurons project to forebrain
structures where information is further integrated. In this study we
used an
ex-vivo
nose-brain preparation to investigate the neural
responses of the medial and non-medial subsystems of the olfactory
bulb to a variety of odours using local field potential and multi-unit
recordings. Response profiles of local field potentials were
monophasic or multiphasic in shape and were consistent within a
given recording location, independent of odour category. The
amplitude, response latency, and half-width of field potential
responses were examined for each odour in both the medial and
non-medial regions of the olfactory bulb. In addition, changes in
spike frequency were examined for multiunit recordings revealing
both excitatory and inhibitory responses to amino aids, sex
pheromones, and migratory pheromones depending on the
recording location within the olfactory bulb. Taken together these
responses suggest that the medial region is responsive to basic
amino acids, lamprey sex pheromones and migratory pheromones
and has the ability to evoke locomotor responses while the other
regions of the olfactory bulb are responsive to a specific subset of
odours suggesting that the olfactory bulb of the sea lamprey
exhibits chemotopy. Acknowledgements: Funding provided by the
Great Lakes Fishery Commission and the Natural Sciences and
Engineering Research Council of Canada.
64 | AChemS Abstracts 2012
Abstracts are printed as submitted by the author(s)
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