| Project/Area Number |
02807131
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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 |
Cerebral neurosurgery
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| Research Institution | Kanazawa University |
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Principal Investigator |
ISHISE Jun Kanazawa University University Hospital Assistant Professor, 医学部附属病院, 講師 (50212882)
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| Co-Investigator(Kenkyū-buntansha) |
HASEGAWA Mitsuhiro Kanazawa University School of Medicine Lecturer, 医学部, 助手 (70218460)
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| Project Period (FY) |
1990 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1992: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1990: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | Nerve regeneration / Transplantation / Axon / Myelin sheath / Node of Ranvier / Ultrastructure / Freeze-Fracture / 超微形態 / フリ-ズフラクチャ- / ナトリウムチャンネル / フリ-ズフラクチャ-法 |
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| Research Abstract |
Peripheral nerve autografts were transplanted either to a peripheral nerve or to the spinal cord to study axonal regeneration and remyelination in rats. The sciatic nerve graft was transplanted to the cut ends of the facial nerve in ten rats and the peroneal nerve graft was to the spinal cord in nine rats. The nerve grafts were examined by electron microscopy after one to 24 weeks. Cation staining and freeze-fracture methods were performed as well to know the further information of sodium channels in axon membrane. In thin sections, a lot of lymphocytes and macrophages were seen with Wallerian degeneration in grafts within four weeks. After four weeks, Schwann cells and unmyelinated fibers were increased in number and thin myelin sheaths and short internodes were observed in sciatic grafts. In peroneal grafts, myelinated and unmyelinated fibers were seen only in two rats although four out of nine showed tight adhesion to the spinal cord in gross inspection. These myelin sheaths were of peripheral type surrounded by collagen fibers. In cation staining, performed only in sciatic nerves, electron-dense patches were seen on the unmyelinated axons and at the node-like areas between short internodes after four weeks. In freeze-fracture replicas, also performed in sciatic nerves, Axolemmal E-face particles were distributed in a concentration of 200/mum^2, half of which were large (>10nm) and were supposed to be sodium channels. In conclusion, an electron microscopic examination of the peripheral nerve graft both into the peripheral and central nervous system showed a number of regenerated unmyelinated and myelinated fibers of peripheral type. Sodium channels were concentrated at the area between the internodes at the early stage of remyelination. Schwann cells directly surrounded the regenerated axons with or without myelin sheaths.
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