ABSTRACT
Recently, there are numerous efforts to explain the psycho-, neurological events through molecular biological standards. Because of the property as a strong stimulant to neural cells, convulsions induced by electroconvulsive shock (ECS) or kainic acid are used for neurobiological research. In this study, the effect of systemic administration of kainic acid and ECS on the expression of hsp 72 mRNA in the rat brain was investigated with in situ hybridization histochemistry. The induction of hsp 72 mRNA was observed in the dentate gyrus from 2 hr after KA treatment. After that, the expression was gradually increased in the various areas including dentate gyrus, hippocampus, olfactory bulb, cerebral cortex, caudate-putamen, thalamus, and peaked at 9 hr after KA treatment. At the 72 hr after KA treatment, weak expression was found only in the CA3 area of hippocampus. However, the expression of hsp 72 mRNA was not detected in any ESC treated rat brains, we examined.The inducton of c-fos was observed from 15 min, peaked at 6 hr, and returned to basal level at 48 hr after KA treatment. The expression of c-fos was observed in the same areas that showed induction of hsp 72 mRNA. In the ECS treated rat brains, the induction of c-fos was found in the dentate gyrus, olfactory bulb and cerebral cortex at 15 min and 30 min after ESC. From these results, it may be suggested that the effects of KA treatment and ECS on the neuronal cells are different, and it is due to difference in induction mechanism of convulsion between KA and ECS. And, the similarity between the expression pattern of hsp 72 mRNA by KA and KA receptor suggests that the induction of hsp 72 mRNA is based on the direct effect of KA through KA receptor.