| Project/Area Number |
14540627
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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 |
動物生理・代謝
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| Research Institution | Nara Women's University |
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Principal Investigator |
OISHI Tadashi Nara Women's University, Graduate School of Humanities and Sciences, Professor, 大学院・人間文化研究科, 教授 (30112098)
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| Co-Investigator(Kenkyū-buntansha) |
TAMOTSU Satoshi Nara Women's University, Faculty of Science, Associate Professor, 理学部, 助教授 (60188448)
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2002: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Photoreception / Circadian Rhythm / Vertebrates / Visual Pigments / Circadian Oscillator / Electrophysiology / Immunohistochemistry / Pineal organ |
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| Research Abstract |
We studied the diurnal changes of several neurosteroids in the newt brain under a semi-natural condition in May. We also examined the effects of removal of the eyes and pineal to clarify the involvement of these organs in the rhythmic changes of neurosteroids. Pregnenolone and progesterone in the brain showed distinct diurnal changes with a peak at 1:00 and at 21:00, respectively, in both intact and eye-removed animals. The effects of pinealectomy and removal of the eyes were very similar to the results of pregnenolone. We further investigated the photoperiodic response of serotonin-and galanin (GA)-immunoreactive (ir) cells in the paraventricular organ (PVO) and infundibular nucleus (IF) of the Japanese quail and the interaction of these cells with gonadotropin-releasing hormone (GnRH)-ir neurons in the hypothalamus. Photoperiods and light-dark cycles showed distinctive effects on the serotonin-ir and GA-ir cell numbers in the hypothalamus. The results together with close relationships between these neurons and GnRH-ir cells and fibers suggest that these substances are important in regulation of photoperiodic gonadal response in Japanese quail.
In lampreys, we found UV-receptor, red-and green-pigments existed in the pineal in addition to rhodopsin by using immunocytochmistry and in situ hybridization methods. We also detected response of UV-receptor electrophysiologically. The UV pigment of lamprey is a parapinopsin homologue that exhibits an absorption maximum at 370nm. UV light causes a cis-trans isomerization of the retinal2 chromophore to form a stable photoproduct having an absorption maximum at 515 nm. The photoproduct revertrs to the original pigment upon visible light absorption.
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