1997 Fiscal Year Final Research Report Summary
Identification of the 'circadian rhythm' oscilating center of goldfish.
| Project/Area Number |
08660239
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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 |
General fisheries
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| Research Institution | Miyazaki Prefectural Nursing University (1997)
Kitasato University (1996) |
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Principal Investigator |
ASANO Masamitsu Miyazaki Prefectural Nursing University, Professor, 教授 (60260858)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMORI Kunio Kitasato University, Department of Fisheries Science, Professor, 水産学部, 教授 (80012029)
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| Project Period (FY) |
1996 – 1997
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| Keywords | SCN / SUPRACHIASMIC NUCLEUS / Circadian rhythm / Goldfish / Brain lesion |
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| Research Abstract |
The present study was constructed to examine that the teleost's SCN (Supra Chyasmic Nucleus) could be a 'circadian rhythm' oscillating center controlling the physiological process to synchronize with daily light-dark cycle, and to establish preliminary the methodology where an electrophiologial analysis on the mechanisms of the SCN spontaneous oscillation independent from daily environmental cycle cues.
Then, 1)SCN lesioning effects were examined on the locomotive activity of goldfish which had been entrained to elevate the activity two times on daytime by restricted feeding, and 2)a phasemodulation effect was tested on the phase daily SCN activity cycle.
By the SCN-lesioning, it was usually observed on the actograms that goldfish's locomotive activities of two-peaks shapes through datime were lost to depending only upon the light-dark cycle. On the other hand, the SCN was found to have a daily cycle of spontaneous action ptentials generation and the phase of which did not easily modulate by synchronizing with the phase-changes of the environmental light-dark cycle. These characteristics of the goldfish's SCN activity coincide with the proper nature of the 'ciradian rhythm' center, although being in consistent with the responses observed in the locomotive activity that modulated its daily cycle phase within 2 or 3 days by synchronizing with the phase change of its environmental light-dark cycle.
The goldfish might activate its locomotion at the feed-times by memorizing the period length from the beginning of the light-phase to the feed-times in refference to the spontaneous SCN oscillation daily cycle.
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