| Project/Area Number |
06671850
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Functional basic dentistry
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
KATAKURA Nobuo Tokyo Medical and Dental University Faculty of Dentistry, Research Associate, 歯学部, 助手 (20185804)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1994: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | trigeminal mesencephalic nucleus / slice preparation / isolated brainstem-spinal cord preparation / ion-channel / rhythm / 舌活動 / 吸啜運動 / スライス標本 / 閉口筋 / 筋紡錘 / 歯根膜機械受容器 / 多極性ニューロン / 偽単極性ニューロン |
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| Research Abstract |
In the trigeminal mesencephalic nucleus (MTN), there are two functional types of neurons : one supplying the muscle spindles in jaw-closing muscles and the other the periodontal mechanoreceptors, and also two anatomical types of neurons : pseudomonopolar and multipolar. The purpose of this study was to investigate the organization of ion-channels on each type of MTN neurons in in vitro preparations.
To achieve this goal, I had developed two types of in vitro preparations : slice preparation and isolated brainstem-spinal cord preparation. Although the slice preparation is of use to an analysis of ion-channels, it will not achieve characterizations of individual cells and a system analysis. On the other hand, the isolated brainstem-spinal cord preparation involves intact circuits including MTN neurons and generates reflex responses and rhythmical activity.
The in vitro brainster-spinal cord preparation were isolated from neonatal rats (from 0- to 3-day-old). Neural activities were monitored in trigeminal sensory (Vs), trigeminal motor (Vm), hypoglossal (Xll) nerves as well as ventral roots of the cervical spinal cord (C4-C5) with suction electrodes. The following results were obtained : (1) electrical stimulation of Vs evoked nerve volley in Vm and Xll ; (2) rhythmical nerve discharges distinct from spontaneously generated respiratory activities recorded in Vm, Xll and C4,5 nerves could be observed in the Xll nerve after application of N-menthyl-D-aspartate into the bath solution.
I conclude that this isolated brainstem-spinal cord preparation will be useful for the investigation of cellular mechanisms (ion-channel) and neuronal organization (system) related to the function of MTN neurons. At present, I am trying to analyze ion-channel mechanisms of MTN neurons in these preparations.
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