| Project/Area Number |
05671900
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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 |
応用薬理学・医療系薬学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
SHIBATA Shigenobu Kyushu Univ., Pharomaceutical Science, Pharmacology, associate professor, 薬学部, 助教授 (10162629)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1993: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Circadian Rhythms / Anticipation / Entrainment / Suprachiasmatic / Acetylcholine / Time cognition / Learning / Activity / 体内時計 / 学習・記憶 / 夜間徘徊 / 生体リズム |
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| Research Abstract |
The suprachiasmatic nucleus (SCN) has been identified as a pacemaker for mammalian circadian rhythms. There are two different entraining pathways : one is retinohypothalamic tract and the othere is geniclohypothalamic tract. As glutamate has been suggested as a transmitter of the retinohypothalamic tract, we examined the effect of NMDA,a glutamate NMDA receptor agonist on the SCN neuronal activity thythem. NMDA produced phase changes similar to light-induced phase shifts through the nitric oxide production in the SCN.In addition, AMPA,an ionotropic glutamate receptor agonist caussed similar phase shifts via the activation of protein synthesis.
Restricted feeding at a fixed time of the day produced an entrainment in hamsters and rats. At present, the neuronal mechanism of this anticipatory food-entrainable rhythms are uncertain. The food-and methamphetamine-associated anticipation were impaired by aging and a treatment with NMDA receptor antagonist, MK-801. The impairment of this anticipation in aging animals was attenuated by cholinergic drugs such as arecoline and physostigmine. In addition, daily lever pressing at a fixed time of day to drink water was also established in operant experiment paradgim. These results suggest that cholinergic drugs may be important in the performance of the anticipatory activity rhythms.
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