1992 Fiscal Year Final Research Report Summary
Basic Aspects of Susceptibility to Seizures in Childhood Epilepsy
| Project/Area Number |
03670504
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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 |
Pediatrics
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| Research Institution | Osaka City University Medical School |
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Principal Investigator |
MURATA Ryosuke Osaka City University Medical School, Associate Professor of Pediatrics, 医学部, 助教授 (20128755)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUOKA Osamu Osaka City University Medical School, Lecturer in Pediatrics, 医学部, 講師 (20117972)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Amygdala kindling / Suckling rats / Entorhinal response / Phosphatidylinositol / Ibotenate / Childhood epilepsy / NMDA受容体 / 痙攣準備性 |
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| Research Abstract |
The experimental model of childhood epilepsy involves kindling of rats, in which repeated electrical stimulation of the brain (usually the amygdala) leads to focal afterdischarges (ADs) and then generalized seizures. We studied the relationship between the duration of ADs and changes in entorhinal responses during amygdala kindling in suckling rats (9-29 days old) in a physiological study, and then investigated the mechanism of kindling by administering ibotenate in a biochemical study of this phenomenon.
In the first study, the entorhinal field potential was recorded with a tungsten wire electrode during amygdala stimulation of anesthetized rats. As rats developed, the amplitude and the latency of the first peak of the negative component increased and decreased, respectively. The half-width of this component decreased. As ADs after a kindling stimulation appeared, this half-width increased. Thus, changes in the entorhinal response were seen as an increase in its half-width as kindling developed.
The second study was done by stimulation of receptors for the excitatory amino acid ibotenate by its administration, which caused phosphatidylinositol (PI) hydrolysis. The effect decreased with the age of the suckling rats. Kindling caused increased hydrolysis. Thus, kindling may reactivate receptors during development, allowing renewed PI hydrolysis. Perhaps increased efficacy of synaptic transmission accounts for the changes observed during kindling and long-lasting susceptibility to seizures.
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