| Project/Area Number |
59480113
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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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 College |
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Principal Investigator |
KIYOHARA Toshikazu Saga Medical College, 医学部, 助教授 (50071874)
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| Co-Investigator(Kenkyū-buntansha) |
KOGA Hisao Saga Medical College, 医学部, 助手 (30153513)
YAMASAKI Mari Saga Medical College, 医学部, 助手 (80174647)
NAKASHIMA Toshihiro Saga Medical College, 医学部, 助手 (30128136)
SHIBATA Masaaki Saga Medical College, 医学部, 助手 (00128133)
HORI Tetsuro Saga Medical College, 医学部, 教授 (00022814)
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| Project Period (FY) |
1984 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1986: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1985: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1984: ¥3,800,000 (Direct Cost: ¥3,800,000)
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| Keywords | Hypothalamus / Thermosensitive neuron / Thermoregulation / Osmosensitive / Osmoregulation / Water balance / Central interaction / Baro |
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| Research Abstract |
To analyze the possible central interaction between thermoregulation and osmoregulation, we have investigated the effect of osmotic and blood pressure changes on the activities of thermosensitive neurons in the preoptic an anterior hypothalamus (PO/AH) where are known to play a cardinal role in thermoregulation.
1. About 60% of PO/AH thermosensitive neurons tested are osmosensitive. Some PO/AH neurons responded to both local an peripheral osmotic sitmuli. The major response pattern was the decreased firing rate of warm sensitive neurons to hyperosmotic stimuli given either locally or peripherally. The reduced activity of PO/AH warm sensitive neurons in a hyperosmotic environment may appropriate to explain, at least in part, the phenomenon of reduced evaporative heat loss in dehydrated mammals.
2. Falls in blood pressure increased and decreased the activity of warm sensitive neurons and cold sensitive neurons respectively. Bilateral denervation of glossopharyngeal, vagus and sympathetic nerve abolished the neuronal responses to blood pressure changes. These neuronal responses during hypotension suggest that at least a part of hypothermia observed during acute hemorrhage in a centrally induced response having a survival value.
3. The unit activities of PO/AH thermosensitive neurons in free-moving rats were modified by not only thermoregulatory behaviors but also non-thermoregulatory behaviors.
4. The results suggest that PO/AH thermosensitive neurons, beside their postulated thermoregulatory functions, might be involved in the coordination of thermoregulation with non-thermal homeostatic functions controlled in the hypothalamus.
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