| Project/Area Number |
15500204
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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 |
Neuroscience in general
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| Research Institution | Gunma University |
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Principal Investigator |
ISHIZAKI Yasuki GUNMA UNIVERSITY, GRADUATE SCHOOL OF MEDICINE, PROFESSOR, 大学院・医学系研究科, 教授 (90183003)
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| Co-Investigator(Kenkyū-buntansha) |
UCHIDA Takayuki GUNMA UNIVERSITY, GRADUATE SCHOOL OF MEDICINE, RESEARCH ASSOCIATE, 大学院・医学系研究科, 助手 (80334093)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2004: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | NEURAL STEM CELL / NEURON / ASTROCYTE / DIFFERENTIATION / PROLIFERATION / CEREBELLUM / GRANULE CELL / PLASTICITY |
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| Research Abstract |
This research aimed at two objects. One was to keep the neuronal precursor cells dividing for long time in culture, and the other was to turn the neuronal precursor cells into the neural stem cells. We examined the cerebellar granule cell precursors (GCPs) in this research.
1.We developed the method for purifying the immature GCPs from the developing mouse cerebellum. To separate immature GCPs from postmitotic GCPs, we used the HNK-1 antibody, which stained only the immature GCPs in the frozen sections of developing cerebella, for sequential immunopanning. We first collected the small cell fraction on a Percoll density gradient. We then removed the microglial cells by negative selection, and positively selected the HNK-1-positive cells. We measured the ability of the cells to incorporate BrdU when stimulated by sonic hedgehog (Shh), a potent mitogen for GCPs. The HNK-1-positive population contained a higher proportion of BrdU-positive cells than did the unsorted cells. The immature GCPs exited the cell cycle, even in the presence of Shh. We are now trying to find a mitogen which would keep the immature GCPs dividing in culture.
2.We found that the immature GCPs can differentiate into astroglial cells when exposed to Shh and bone morphogenetic proteins (BMPs). These induced cells initially expressed both glial fibrillary acidic protein (GFAP) and neuronal markers, but then lost their neuronal markers and acquired S100-β, a marker of differentiated astroglial cells. These results indicate that some GCPs are not irreversibly committed to neuronal development, but can be induced to differentiate into astroglial cells by appropriate extracellular signals. We also found nestin-positive cells in the developing cerebellum, which proliferate extensively in response to epidermal growth factor (EGF). These cells self-renew, and differentiate into neurons and astroglial cells. We are now trying to identify which cell type these cells originate from.
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