| Project/Area Number |
12680746
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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 |
Neurochemistry/Neuropharmacology
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
MURAKOSHI Takayuki Tokyo Med. & Dent. Univ., Pharmacol. & Neurobiol., Associate Prof., 大学院・医歯学総合研究科, 助教授 (60190906)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2001: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2000: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | oscillatory neural activity / synchronous neural activity / consciousness / cerebral cortex / thalamus / local neural circuit / calcium channel / brain slice / 同期神経活動 |
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| Research Abstract |
The oscillatory and/or synchronous neuronal activities are considered to play important roles in maintenance of the consciousness and in performance of higher CNS functions. In order to elucidate the mechanisms controlling the oscillatory activity in terms of io* channels and local network, spontaneous or stimulus-evoked oscillatory excitation wa* recorded electrophysiologically from the slice preparation which reserved thalamo-cortica* neural connections. Optical recordings of the membrane potential using a voltage-sensitive dye revealed that the thalamus and the primary somatosensory area (the barrel cortex) are connected within the slice plane. Using whole-cell patch-clamp methods, 10-40 Hz fluctuation of the membrane voltage/current for 1-2 s was observed in response to tetani* stimulation of the internal capsule which supplies inputs to the cortex. However, this oscillatory activity was not affected by application of Ni (a blocker of the T-type and R-type voltage-dependent calcium channels: VDCC) or bicuculline (a GABAA receptor antagonist), suggesting that the activity is neither derived from the network interactions an* nor strongly dependent on the above-mentioned VDCCs. Therefore, strategy was slightl* modified to pursue the network oscillations in the hippocampal CA3 region. The agent which increase neuronal excitability such as carbachol induced an increase in the neuronal activities of >10 Hz and a decrease in those of lower frequency. This action was dependent on the temperature of the perfusate and on the age of the animals from which the preparations were obtained. Propofol, an intravenous anesthetic, reduced the action c* carbachol to induce oscillation.
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