| Project/Area Number |
08680888
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
神経・脳内生理学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
KOYANO Konomi Kyoto University Graduate school of Medicine, 医学研究科, 講師 (50183041)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1996: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | olivocochlear neuron / cholinergic neuron / transient outward current / slice preparation / whole-cell recording / firing properties / オリーブ-蝸牛束神経 / 逆行性生体染色 / 一過性K電流 |
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| Research Abstract |
The cochlea recieves an efferent innervation from olovocochlear neurons(OC)located in the superior olivary complex OC neurons have been anatomically classified into two groups by their origins and targets ; the lateral and medial OC (LOC and MOC,respectively) neurons. The majority of OC neurons is known to be cholinergic from histochemical investigations. Both groups of OC neurons recieves excitatory voley from afferent auditory tract. Thus, OC neurons form reflex arch to regurate peripheral auditory signal processing Because of the difficulty of their identfication in slice preparation, there were few direct electrophysiological study of OC neurons in spite of their physiological significance. We succeeded to stain living OC neurons by retrograde labeling. Stained OC neurons were identified under a fluorescence microscope and they were sujected to whole-cell recording. LOC and MOC neurons had different electrophysiological properties. When the membrane was slightly hyperpolarized (-72 to -76 mV), LOC neurons showed spike trains with along first interspike interval, whereas MOC neurons showed spike trains with a long latency to the first spike. Under voltage clamp, LOC neurons revealed two transient outward current with different inactivation kinetics. In MOC neurons, there was only one transient outward current. The different expression of these transient outward current between LOC and MOC neurons seems to be responsible for the difference in firing properties of these two groups of neurons.
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