2003 Fiscal Year Final Research Report Summary
Cell Lineage Analysis of the Forebrain Structures
| Project/Area Number |
14380344
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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 |
Developmental biology
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| Research Institution | Kumamoto University |
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Principal Investigator |
SHIMAMURA Kenji Kumamoto University, Institute of Molecular Embryology and Genetics, Professor, 発生医学研究センター, 教授 (70301140)
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| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Daisuke Kumamoto University, Institute of Molecular Embryology and Genetics, Research Associate, 発生医学研究センター, 助手 (00363507)
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| Project Period (FY) |
2002 – 2003
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| Keywords | neuroepithelium / neural stem cell / cell lineage / gene expression / cell migration / regionalization / brain nucleus / thalamus |
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| Research Abstract |
The aim of this research project was to elucidate the origin of neurons that constitute certain brain structures upon the sheet of neuroepithelium. As a first step to this end, we have focused on the thalamic region of the brain which consists of clusters of neurons called brain nuclei to address how these neurons are specified and how these nuclear structures are formed during development. We have found that several transcription factors are expressed in the specific brain nuclei in the thalamus. The onset of their expression was found in distinct populations of the postmitotic cells in the early mantle layer of the thalamic rudiment, which was regulated by the differential activities of Sonic hedgehog in a manner consistent with its action as a morphogen. Such distinct inductive activities are mediated selectively by different Gli factors. Next we found that some neuronal populations migrate from their birthplace to the particular nuclei through highly stereotyped pathways. Transplantation experiments revealed that this migratory property is unique to the particular populations, and dependent on the surrounding environment. These results suggested a scenario that (1) the relatively simple pattern created early in development in part by inductive mechanisms leads to generation of distinct neuronal populations at defined locations within the thalamic rudiment, and (2) these distinct populations then undergo specific migration intrinsic to them, which may eventually generate more complicated patterns such as the nucleus organization in the developed thalamus. We think that these processes are likely to be basic strategies for the formation of the nuclear structures.
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