2015 Fiscal Year Final Research Report
Search of the novel pineal humoral factor in a mammalian circadian system
| Project/Area Number |
26860163
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Environmental physiology(including physical medicine and nutritional physiology)
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| Research Institution | Kinki University |
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Principal Investigator |
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| Project Period (FY) |
2014-04-01 – 2016-03-31
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| Keywords | 松果体 / 視交叉上核 / 概日時計 / メラトニン |
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| Outline of Final Research Achievements |
The functions of humoral factors except melatonin in the pineal body on the light entrainment of the circadian rhythm have not been fully investigated. In melatonin-proficient CBA/N or melatonin-deficient C57BL/6 mice, pinealectomy induced faster resetting for jet-lag. Administration of melatonin to the pinealectomized CBA/N mice did not modify the recovery from the jet lag. 5-HT showed apparent effects on the light resetting process. 5-HT delayed the resetting of locomotor activity rhythm after an abrupt shift of LD cycle, and attenuated the pinealectomy-enhanced phase shift of the circadian locomotor activity as well as c-Fos induction in the SCN after a light pulse during the night. In contrast, 5-HT synthesis inhibitor generated increase of the phase shift as well as increase in c-Fos induction by light. The findings suggest that pineal 5-HT suppresses light entrainment by attenuating the light signal transduction to the central circadian clock in the SCN.
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| Free Research Field |
動物生理学
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