Abstracts - Association for Chemoreception Sciences

#P105 POSTER SESSION II:
OLFACTION DEVELOPMENT; TASTE CNS;
NEUROIMAGING; OLFACTION CNS
Influences of lateral amygdala activation on piriform cortical
odor processing
Benjamin Sadrian 1,2 , Donald Wilson 1,2
1
NYU School of Medicine New York, NY, USA, 2 Nathan Kline
Institute Orageburg, NY, USA
Olfactory sensory processing in the piriform cortex requires the
synergy of odorant ligand input, local inhibitory feedback loops,
and interregional modulation, in order to synthesize emotionally
relevant and contextually significant odor percepts. Reciprocal
connectivity between the piriform cortex and higher processing
regions, such as the lateral entorhinal cortex and amygdala,
provide currently understudied routes through which odor
processing in the piriform may be regulated. We have employed
optogenetic techniques to investigate how activation of lateral
amygdala (LA) during odor presentation affects piriform cortical
odor processing. We have performed single unit recordings
of both spontaneous and odor-evoked activity in the anterior
piriform cortex, and summarized a range of LA-influenced
changes in piriform activity. We have also begun using a fear
conditioning model to investigate the influences of emotional
significance on odor processing in the piriform. We aim to
describe how such contextual changes affect the precision of
both cortical odor processing and behavioral odor perception.
Acknowledgements: T32-MH067763 from the NIMH to B.A.S.
and R01-DC003906 from the NIDCD to D.A.W.
#P106 POSTER SESSION II:
OLFACTION DEVELOPMENT; TASTE CNS;
NEUROIMAGING; OLFACTION CNS
Wild Scents: comparing the olfactory anatomy of caged and
wild mice
Ernesto Salcedo, Kyle Hanson, Taylor Jonas, Lois Low, Diego Restrepo
University of Colorado School of Medicine Aurora, CO, USA
We have previously detailed the subtle neuroanatomical changes
we found in the glomeruli of olfactory bulbs from genetically
identical mice reared in cages with different levels of ventilation
(Oliva and Salcedo et al, 2010). In these mice, we were able
to correlate these glomerular changes with marked increases
in aggressive behavior towards invader mice, highlighting the
exquisite sensitivity a mouse’s olfactory neuroanatomy has to
its environment. In order to examine the broader effects that
environment may have on the formation of the olfactory system,
we have trapped wild house mice from the Denver environs
and have rigorously characterized the neuroanatomy of their
main olfactory bulbs (MOB) using MATLAB mapping software
developed in-house and immunohistochemical techniques. On
gross examination, the MOBs from the wild mice do not appear
to be significantly different from their caged brethren. Nor did
we find any significant immunostaining differences in OMP
of GAP43 labeling of the MOB. Although somewhat smaller,
the wild olfactory bulbs had an estimated number of glomeruli
(using Meisami’s Correction) that does not differ significantly
from the estimated number of glomeruli found in the MOBs
of their caged counterparts. Curiously, we do find a dramatic
difference in the distribution of olfactory sensory innervation
across the surface of the MOB: caged mice tended to have larger
glomeruli that occupied a significantly larger portion of the
glomerular layer then did the wild mice. This distribution was
particularly pronounced in the ventro-medial portion of the bulb
around the AOB. These results provide further evidence that
olfactory environment plays a role in fine-tuning the formation
and maintenance of glomeruli in the main olfactory bulb.
Acknowledgements: NIDCD
#P107 POSTER SESSION II:
OLFACTION DEVELOPMENT; TASTE CNS;
NEUROIMAGING; OLFACTION CNS
Assessment of nasally administered insulin-like growth
factor-I accumulation in the cerebrum of mice with resected
olfactory bulb
Hideaki Shiga 1,2 , Mikiya Nagaoka 2 , Kohshin Washiyama 2 ,
Junpei Yamamoto 1 , Ryohei Amano 2 , Takaki Miwa 1
1
Otorhinolaryngology, Kanazawa Medical University Ishikawa, Japan,
2
Quantum Medical Technology, Kanazawa University Ishikawa, Japan
Objectives: To show the role of the olfactory bulb in the delivery
of nasally administered insulin-like growth factor-I (IGF-I) to the
brain in vivo. Nasal administration of IGF-I has been shown to
enable drug delivery to the brain beyond the blood brain barrier
in vivo. IGF-I is associated with the development and growth
of the central nerve. Methods: The ratio of uptake of nasally
administered 125 I-IGF-I in the cerebrum to uptake in the blood
of male ICR mice with resected left olfactory bulb (8 weeks of
age, the model mice) was compared to that of the sham-operated
male ICR mice (8 weeks of age, the control mice). We exposed
and resected the left olfactory bulb, cutting the frontal bones of
model mice, and just exposed the left olfactory bulb in control
mice under anesthesia. 125 I-IGF-I (human, recombinant) saline
solution was obtained from PerkinElmer Japan (Yokohama,
Japan), and 10μl was instilled into the left nostril of each mouse
with a microinjection pipette under anesthesia. The radioactivity
of the samples was measured with gamma spectrometry. The
accumulation of the nasally administered neuronal tracer
(fluoro-ruby; dextran tetramethylrhodamine) in the epithelium
of mice was assessed in frozen sections under a fluoroscopic
microscope. Results: The ratio of uptake of nasally administered
125
I-IGF-I in the cerebrum to uptake in the blood of the model
group was significantly decreased compared to the control group.
The accumulation of nasally administered neuronal tracer in
the nasal epithelium of mice was significantly prevented by the
resection of the olfactory bulb. Conclusions: Olfactory bulb
resection results in the reduced delivery of nasally administered
IGF-I to the brain due to the disconnection of the olfactory
nerve between the nasal epithelium and olfactory bulb in vivo.
Acknowledgements: Grant-in-Aid for Scientific Research
from the Ministry of Education, Science and Culture of Japan
(C21592174 to H.S.) and Assist Kaken from Kanazawa Medical
University (J.Y.)
POSTER PRESENTATIONS
Abstracts are printed as submitted by the author(s).
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