1995 Fiscal Year Final Research Report Summary
Coding of odor molecules by neurons in mammalian olfactory bulb and cortex : Functional role of olfactory glomeruli
| Project/Area Number |
05454684
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
神経・脳内生理学
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| Research Institution | OSAKA BIOSCIENCE INSTITUTE |
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Principal Investigator |
MORI Kensaku Osaka Biosci.Inst.Dept.Neurosci.Vice-Head, 第3研究部, 副部長 (60008563)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIHARA Yoshihiro Osaka Med.Coll.Dept.Biochem.Asso.Prof., 医学部, 助教授 (20220717)
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| Project Period (FY) |
1993 – 1995
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| Keywords | Odor Molecule / Olfactory Bulb / Olfactory Cortex / Mitral Cell / Granule Cell |
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| Research Abstract |
1) Molecular receptive range properties of mitral/tufted cells in the rabbit main olfactory bulb
Recording of extracellular spike responses were made from single mitral/tufted cells in various regions of the main olfactory bulb of urethane-anesthetized rabbits. Examination with an expanded panel of stimulus odor molecules that included both aromatic and aliphatic compounds indicated that single mitral/tufted cells show excitatory spike responses to a range of odor molecules (molecular receptive range) having similar conformations. These results support the hypothesis that conformational parameters of ligand odor molecules play a key role in sensory processing in the olfactory bulb. In addition, the results are in agreement with the hypothesis that sensory neurons expressing the same type of odor receptor converge on one or a few glomeruli.
2) Functional role of bulbar local circuit neurons in coding of odor molecules
Using single unit recording in rabbit main bulb, we showed that inhibitory responses are evoked in mitral/tufted cells by a defined subset of odor molecules with structures closely related to the excitatory odor molecules. Pharmacological blockade of the dendrodendritic synaptic transmission between mitral/tufted and granule cells markedly decreased the odor evoked suppression, suggesting that the inhibitory responses are evoked by lateral inhibition via the dendrodendritic synaptic pathway. The synaptic interaction s within the local circuits in the bulb, thus, greatly enhance the tuning specificity of odor responses and contribute to discrimination of odor molecule information.
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Research Products
(12 results)
