| Project/Area Number |
07458219
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | NIIGATA UNIVERSITY |
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Principal Investigator |
BANDO Takehiko Niigata University School of Medicine, Department of Physiology, Professor, 医学部, 教授 (50029534)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥6,400,000 (Direct Cost: ¥6,400,000)
Fiscal Year 1996: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1995: ¥4,000,000 (Direct Cost: ¥4,000,000)
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| Keywords | ocular convergence / long-lasting potentiation / cat / extrastriate cortex / glutamate blockers / visual stimulation / intracortical stimulation / lateral suprasylvian cortex / 大脳 / 視覚領 / 眼球運動 / 輻輳 / 組み合せ刺激 / 神経生理学 |
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| Research Abstract |
Amplitudes and velocities of converqence eye movement were increased for 6-24 hours after 30-50 trials (20-30 min) of combined visual and intracortical stimulation in alertand trained cats. Necessary surgeries were performed in advance under deep nembutal anesthetic. In these surgeries, an adapter for a head holder, a chamber for electrode penetration, and eye coils were implanted. Movement of a visual target approached to the cat under computer control was used for visual stimulation. Eyemovement was measured by a magnetic serach coil system. Effective sites for intracortical microstimulation to induce long-lasting potentiation of ocular convergence in combination with visual stimulation were limined in the convergence-related regions in the lateral suprasylvian (LS) visual cortex, reported by Toda et al.(1991). Combination of two stimuli with random intervals or with longer intervals of 4 sec were ineffective to induce long-lasting potentiation, supporting the essential requirement of combination of visual and intracortical stimulation.
Long-lasting potentiation of ocular convergence was inhibited by iontophoretic injection of CNQX (a blocker of AMPA-type glutamate receptor), AP5 (a N-MDA blocker) and H7 (a protein kinase inhibitor). The former is known to block visual responses of LS neurons, and the latter two drugs has been related to synaptic long-term potentiation.
From these results it is concluded that the mechanisms in the LS cortex are responsible for long-lasting ocular convergence. It is also suggested that long-lasting potentiation of ocular convergence shares some basic mechanisms with synaptic long-term potentiation.
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