1995 Fiscal Year Final Research Report Summary
Analysis of newly formed neuronal cuircuit in the adult hippocompal formation
| Project/Area Number |
05808071
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Nerve anatomy/Neuropathology
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| Research Institution | Juntendo University School of Medicine |
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Principal Investigator |
SEKI Tatsunori Juntendo University School of Medicine, Anatomy, Lecturer, 医学部, 講師 (20175417)
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| Project Period (FY) |
1993 – 1995
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| Keywords | hippocampus / neural cell adhension molecule / neural development |
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| Research Abstract |
Many ^3H-thymidine autoradiographic studies have repeatedly shown that adult neurogenesis occurs in the innermost portion of the granule cell layr of the hippocampal dentate gyrus. Since the hippocampal formation has been found to display a remarkable form of plasticity and to play a key role in establishing memory and learning, it is assumed that the adult neurogenesis is related to these hippocampal functions. Recently we have found that a highly polysialylated neural cell adhesion molecule (NCAM-H) is a reliable molecular marker for newly generated granule cells. Using immunohistochemistry for NCAM-H, we have revealed the neuronal circuit formed by newly generated granule cells as follows.
(1) The number of newly generated granule cells gradually decreased over more than one year, but they were still detected in 18-month-old rats. These findings indicate that although newly generated granule cells are continuously forming new neuronal circuit in the adult hippocampal formation, the number of these cells decreases with aging.
(2) The completion of synapse formation on the dendrites and axon terminals of the newly generated granule cells coincide with the cease of NCAM-H expression.
(3) The dendrites of the newly generated granule cells develop in contact with the processes of the radial glia.
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