1998 Fiscal Year Final Research Report Summary
The role of mossy fiber sprouting, neuronal death and glial activation in epileptogenesis
| Project/Area Number |
09470207
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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 |
Psychiatric science
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| Research Institution | Tohoku University |
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Principal Investigator |
SATO Mitsumoto Tohoku University Medicine Professor, 医学部, 教授 (70033321)
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| Co-Investigator(Kenkyū-buntansha) |
NUMACH Yotaro Tohoku University Department of Psychiatry Lecturer, 医学部・附属病院, 講師 (00261636)
MATSUOKA Hiro Tohoku University Medicine Associate Professor, 医学部, 助教授 (00173815)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Kindling / mossy fiber sprouting / neuronal death / hippocampus / glia / neuroqenesis |
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| Research Abstract |
Hippocampal sclerosis (HS) is the most common neuropathological change which frequently observed in temporal lobe epilepsy. The major neuropathology of HS is neuronal loss, gliosis and mossy fiber sprouting (MFS) in the hippocampus. Recent experimental evidence suggests the origin of MFS.Neuronal loss in the hilar polymorphic neuron leads aberrant axonal sprouting from preexisting mature dentate granule cells in to the inner molecular layer. And another suggest that neurogenesis in dentate gyms was increased by brain insult that newly born granule cells project axons in to inner molecular layer.
The main objective of the present study is to clarify the origin of MFS using daily amygdala kindling. For this purpose, first we consider when MFS occurs, next using in situ terminal deoxynucleotigyltransferasemediated dUTP nick-end labeling (TUNEL) method to detect neuronal death in the dentate gyrus, and to detect neurogenesis of granule cells using bromodeoxyuridine (BrdU), and finally using immunohistological methods to examine the activation of glial cells which may participate with axonal sprouting.
The result were the kindling develop without MFS or neuronal death in hilus region. There were significant TUNEL positive cells after repetition of 18 afterdischarges or 10 generalize convulsions. Astrocyte was activated at the stage when sprouting occur and microglia was activated at the stage when TUNEL positive neuron was significant in granular cell layer. The degree of neurogenesis of granule cell correlate with the severity of seizure.
From these result it may suggest MFS originate from newly born granule cells after kindling developed and astrocyte may participate with axonal sprouting.
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