| Project/Area Number |
63570081
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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 |
環境生理学(含体力医学･栄養生理学)
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| Research Institution | Saga Medical School |
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Principal Investigator |
NAKASHIMA Toshihiro Saga Medical School, Physiology Assistant, 医学部, 助手 (30128136)
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| Co-Investigator(Kenkyū-buntansha) |
KIYOHARA Toshikazu Saga Medical School, Physiology Associate Professor, 医学部, 助教授 (50071874)
森 俊憲 佐賀医科大学, 医学部, 助手 (40200373)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1989: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1988: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | thermoreception / Na^+ channel / suction electrode method / thermosensitive neuron / hypothalamus / 温度感受性ニューロン |
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| Research Abstract |
The ionic current responses to temperature of dissociated cells from the preoptic and anterior hypothalamus (PO/AH) of rat were investigated, using the 'whole-cell' configuration. The majority of the recorded neurons showed a linear increase in a non-inactivating inward current during warming (32 to 40ﾟC), and the Q_<10> was about 2. This current is mainly caused by Na^+-influx because the inward current was reduced by half when external solution was substituted choline for half of Na^+. On the other hand, about 24% of PO/AH neurons were markedly sensitive to warming and the increase in non-inactivating inward current to a rise in temperature in hyperthermic range (35-40ﾟC) had a high Q_<10> (4.3-7.0). This increase in current in the hyperthermic range was reversibly blocked by tetrodotoxin (TTX). The inward current in neurons with a Q_<10> of 2 was not affected by TTX. The results show that some neurons in the PO/AH possess a non-inactivating sodium channel that is highly temperature-sensitive in the hyperthermic range. These neurons should be the 'primary' warm-sensitive neurons which are thermometer in the brain.
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