Molecular biological and electrophyrsiological studies of extranodal matrices on the saltatory conduction of the optic nerve
| Project/Area Number |
15591857
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ophthalmology
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| Research Institution | OKAYAMA UNIVERSITY |
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Principal Investigator |
OOHASHI Toshitaka OKAYAMA UNIVERSITY, GRADUATE SCHOOL OF MEDICINE AND DENTISTRY, LECTURER, 大学院・医歯学総合研究科, 講師 (50194262)
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| Co-Investigator(Kenkyū-buntansha) |
NINOMIYA Yoshifumi OKAYAMA UNIVERSITY, GRADUATE SCHOOL OF MEDICINE AND DENTISTRY, PROFESSOR, 大学院・医歯学総合研究科, 教授 (70126241)
李 勝天 岡山大学, 大学院・医歯学総合研究科, 助手 (90325093)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2004: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2003: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Bral1 / Hapln2 / proteoglycan / hyaluronan / knockout mice / optic nerve |
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| Research Abstract |
The Bral1/Hapln2 proteins are expressed specifically at the nodes of Ranvier in the central nervous system and supposed to be important for the maintenance of matrix molecules by stable binding on the hyaluronan. To explore the role of the extranodal matrices on the saltatory conduction, we analyzed the Bral1/Hapln2 knockout mice.
1.Immunohistochemical and electronmicroscopic analysis
There was no obvious alteration on the formation of paranodes, which is consisted of glial cell (oligodendrocyte) and neuron (axon) interactions. There was also no obvious effect on the clustering of Na+ channels, which is essential for the production of action potentials and propagation of the signals.
2.Electrophiological analysis
However, when we compared the speed of propagation of action potentials on the optic nerves via electrophysiological measurement, there was a significant difference between wild type and Bral1/Hapln2 deficient mice. To figure out those differences, we investigated further the diff
… More
erences of the extranodal matrices as well as the attachment of the endofoot of astrocyte at the node. We could find the mislocalization of several ECM molecules including versican (a chondroitin sulfate proteoglycan), tenascin-R and others in the Bral1/Hapln2 deficient mice. During those analyses, we could find one ECM molecule, which has not reported so far to localize at the nodes of Ranvier, is colocalizing and stabilized with Bral1/Hapln2. Nevertheless, there was no obvious difference of the attachment of the endofoot of the astrocyte.
3.Possible physiological roles of the extranodal matrix
Collectively, there was no obvious difference in formation of paranodes and astrocyte foot process via glial and neuronal cell interactions. We could only observe the difference in the formation of the structure of extranodal matrices. Therefore, we assume that the complex of matrix molecules consisting of chondroitin sulfate proteoglycans and other glycoprotein is contributing to the maintenance of the microenvironment around the nodes. Possibly, it can serve as a Na+ ion-pool, which is important for generating the action potentials via influx through the voltage dependent Na+ channels at the nodes. Less
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Report
(3 results)
Research Products
(13 results)
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[Journal Article] Lp3/Hapln3, a novel link protein which colocalizes with versican and is coordinately upregulated by platelet-derived growth factor in arterial smooth muscle cells2004
Author(s)
Ogawa H, Oohashi T, Sata S, Bekku Y, Hirohata S, Nakamura K, Yonezawa T, Kusachi S, Shiratori Y, Ninomiya Y
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Journal Title
Matrix Biol. 23
Pages: 287-298
Description
「研究成果報告書概要(欧文)」より
Related Report
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[Journal Article] Molecular cloning of Bral2, a novel brain-specific link protein, and immunohistochemical colocalization with brevican in perineuronal nets.2003
Author(s)
Bekku Y, Su WD, Hirakawa S, Fassler R, Ohtsuka A, Kang JS, Sanders J, Murakami T, Ninomiya Y, Oohashi T
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Journal Title
Mol.Cell.Nourosci. 24
Pages: 148-159
NAID
Description
「研究成果報告書概要(欧文)」より
Related Report
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