ELECTROCONVULSIVE SHOCK REDUCES INOSITOL 1,4,5-TRISPHOSPHATE 3-KINASEMESSENGER-RNA EXPRESSION IN RAT DENTATE GYRUS

We investigated the expression of inositol 1,4,5-trisphosphate (InsP(3 )) 3-kinase mRNA after a single electroconvulsive shock (ECS) with in situ hybridization histochemistry in rat brain. At 6 h after ECS, the expression was markedly decreased in the dentate gyrus, and the decrea se was maintained until 9 h with a slight recovery. The InsP(3) 3-kina se mRNA content returned to basal levels after 12 h. We could not dete ct any apparent changes in the expression of InsP(3) 3-kinase mRNA in the CA1-CA3 areas of hippocampus, the striatum, and the cerebral corte x at any time point examined. In the temporal pattern, the reduction o f the expression in the dentate gyrus was preceded by the induction of c- fos after ECS. These observations suggest that the InsP(3) 3-kinas e might be one of the genes whose expression can be altered by ECS.