2003 Fiscal Year Final Research Report Summary
Inhibitory factors of central myelin formation-on the basis of comparative and developmental study on the lemma cribrosa sclerae of the optic nerve
| Project/Area Number |
14370001
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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 |
General anatomy (including Histology/Embryology)
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
INOUE Yoshiro Hokkaido Univ., Graduated School of Medicine, Prof., 大学院・医学研究科, 教授 (20051584)
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| Co-Investigator(Kenkyū-buntansha) |
IKENAKA Kazuhiro Okazaki National Research Institutes, National Institute for Physiological Sciences, Prof., 生理学研究所, 教授 (00144527)
TAKAYAMA Chitoshi Hokkaido Univ., Graduated School of Medicine, Associate Prof., 大学院・医学研究科, 助教授 (60197217)
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| Project Period (FY) |
2002 – 2003
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| Keywords | myelin formation / oligodendrocytes / optic nerve / amina cribrosa sclerae / unmyelinated nerve fibers / astrocytes / glical cells / cell fifferentiation |
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| Research Abstract |
In the mouse optic nerve, the optic nerve fiber layer in the retina, the optic papilla and the lamina cribrosa sclerae (LCS) just after penetrating the eyeball failed to generate myelin, whereas the optic nerve proper in the orbit was occupied by myelinated nerve fibers. The present study investigated development of the architecture of LCS, where the axons develop from unmyelinated to myelinated type, to elucidate how the initial part of axons was unmyelinated. At the LCS of the adult optic nerve, well developed astrocytes densely formed a cytoplasmic mesh-like frame through which unmyelinated fibers passed. The astrocytes here contained numerous and densely packed intermediate glial filaments and cell organelles. This framework formed by astrocytes appeared to be completed between 7 and 14 postnatal days before oligodendrocyte progenitors, migrated from the chiasm side, reached the proximal end of LCS, and began myelin formation. Thus the failure in myelin formation at the intraocular part and LCS possibly depended upon unsuccessful migration of oligodendrocytes beyond LCS constructed by specialized astrocytes, although other inhibitory factors for myelin formation, such as adhesion molecules distributed around LCS, may be unsolved.
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