Developmental and comparative studies of the glial complex in white matter
Project/Area Number |
07457006
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
General anatomy (including Histology/Embryology)
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Research Institution | Iwate Medical University |
Principal Investigator |
SUZUKI Mitsuru School of Medicine, Iwate Medical University Lecturer, 医学部, 講師 (10196876)
|
Co-Investigator(Kenkyū-buntansha) |
MASUDA Tomoyuki School of Medicine, Iwate Medical University Associate Professor, 医学部, 助教授 (10199698)
|
Project Period (FY) |
1995 – 1996
|
Project Status |
Completed (Fiscal Year 1996)
|
Budget Amount *help |
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1996: ¥1,000,000 (Direct Cost: ¥1,000,000)
|
Keywords | regeneration / hippocampus / fimbria / white matter / glia / oligodendrocyte / astrocyte / microglia / 乏宅起細胞 / アポトーシス |
Research Abstract |
The ultrastructure of developing oligodendrocytes in the interfascicular glial complex was examined by means of the criteria of Mori and Leblond (JCN 139 : 1-30,1970). The time course of myelination as related to the maturation of the oligodendrocytes was also investigated. Horizontal and transverse sections of fimbria were prepared for both electron microscopic and immunohistochemical studies. Few scattered glioblasts at PO became transformed into longer unicellular rows by P7, and the glial rows mainly consisted of light oligodendrocytes at P7. Medium oligodendrocytes became dominant in the glial rows at P28. Dark oligodendrocytes appeared at P28 and increased until P60 when the fimbria had an almost adult form with densely packed dark oligodendrocytes. Heterogeneity of the interfascicular glial rows was particularly prominent, and in addition unclassified intermediate types of oligodendrocytes were often observed from P14 to P28. Both mitoses and apoptosis in the glial rows were con
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firmed at the electron microscope level. Some of the apoptotic glia were immunohistochemically proved to be astrocyte. Glial interactions such as Thymosin-positive microglia surrounding apoptotic cells and astrocytic processes with direct contact to adjacent oligodendrocytes were observed. Myelinated fimbrial fibers were identified at P10, and the average number of laminae of the myelinated fibers significantly increased about three times from P10 to P60 (p<0.01). The rate of myelinating fibers among the whole fibers also significantly increased from 14.5% (P14) to 71.5% (P60) (p<0.01). In the multifocal developing pattern of the glial complex, oligodendrocytes seemed to mature continuously and independently repeating mitoses and apoptosis in each glial focus. We also investigated axon-glia interactions using scanning electron microscope and confocal microscope. Theoretical 'woven' meshwork of axons and glial processes in the central white matter was confirmed by the scanning electron microscopic observation. Less
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Report
(3 results)
Research Products
(13 results)