Electrophysiological Studies on Tests on the Effect of Metabolism Improving Agents

Abstract

The effect of destruction of the internal capusule, caudate, globus pallidus and putamen on threshold of the arousal reaction and evoked muscular discharge due to stimulation of cerebral cortex, photo-evoked eyelid microvibration (MV) and photopalpebral reflex (PPR) was investigated in the rabbit.
The effect of administration of CDP-choline and TRH for 4 weeks was investigated using rabbits with experimentaly damaged internal capusule, and for the influence of stopping the administration of these drugs at the 2 weeks was also investigated.
EEG activity following IC destruction was studied in rabbits by the topographic system.
1) The threshold of the arousal reaction and evoked muscural discharge increased markedly following internal capusule destruction.
2) The threshold increased slig htly following caudate, globus pallidus and putamen destruction, but did not show prominent changes in comparison with internal capusule des t r uction.
3) The changes in amplitude of MV following internal capusule destruction was di vided into 2 groups, one in which the amplitude is decreased and the other in which the amplitu d e is increased.
4) The amplitude of MV was increased after caudate and putamen destruction, and was decreased after globus pallidus destruction.
5) The amplitude of the late comp onents (PPR₅-PPR₉) was depressed by internal capusule destruction, slightly intensified by caudate and putamen destruction, and slightly d e p ressed by globus pallidus destruction.
6) The increase of thre shold in the arousal reaction and the evoked muscular discharge by internal capusule destruction was suppressed by administration of CDP-choline and TRH.
7) TRH had a greater effect on the threshold of arousal reaction, while CDP-choline had a greater effect on the threshold of evoked muscular discharge.
8) The suppressed amplitude of MV by internal capusu le destruction was restored and the increased amplitude of MV by internal capusule destruction was suppressed by admini s tration of CDP-choline.
9) The suppressed amplitude of MV by internal capusule destruction was restored and the increased amplitude of MV by internal capusule destruction was more greatly increased b y administration of TRH.
10) The suppressed ampulitude of the late components of PPR by internal capusule destruction was restored by the administration of CDP-choline.