| Project/Area Number |
14380372
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Neuroscience in general
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| Research Institution | Osaka Bioscience Institute |
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Principal Investigator |
IKEDA Masayuki Osaka Biosci.Inst., dept.of Mol.Behav.Biol., Research Associate, 分子行動生物学部門, 研究員 (10288053)
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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 |
¥15,000,000 (Direct Cost: ¥15,000,000)
Fiscal Year 2003: ¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 2002: ¥7,800,000 (Direct Cost: ¥7,800,000)
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| Keywords | endogenous clock / suprachiasmatic nucleus / Ca^<2+> imaging / circadian rhythms / Gene-gun / fluorescent protein / cell cultures / nueronal nucleus |
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| Research Abstract |
Intracellular free Ca^<2+> regulates diverse cellular processes, including membrane potential, neurotransmitter release, and gene expression. To examine the cellular mechanisms underlying the generation of circadian rhythms, nucleus-targeted and untargeted cDNAs encoding a Ca^<2+>-sensitive fluorescent protein (yellow cameleon-2.1) were transfected into organotypic cultures of mouse suprachiasmatic nucleus (SCN), the primary circadian pacemaker. Circadian rhythms in cytosolic but not nuclear Ca^<2+> concentration were observed in SCN neurons. The cytosolic Ca^<2+> rhythm period matched the circadian multiple-unit-activity (MIUA)-rhythm period monitored using a multiple-electrode-array, with a mean advance in phase of 4 hours. Tetrodotoxin blocked MIUA, but not Ca^<2+> rhythms, while ryanodine and 8-bromo-cyclic ADP ribose damped both Ca^<2+> and MUA rhythms. These results demonstrate cytosolic Ca^<2+> rhythms regulated by the Ca^<2+> release from ryanodine-sensitivie stores in SCN neurons.
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