MKP-1 INDUCED IN RAT-BRAIN AFTER ELECTROCONVULSIVE SHOCK IS INDEPENDENT OF REGULATION OF 42-KDA AND 44-KDA MAPK ACTIVITY

Electroconvulsive shock (ECS) activates MAPKs in rat brain and also in duces immediate early genes. We investigated whether ECS induces MKP-1 , a specific MAPK phosphatase and an immediate early gene, for feedbac k regulation of MAPK activity. ECS induced MKP-1 in the cortex, but MA PK activity returned to its basal level before MKP-1 protein increased , within 10 min of ECS. MKP-1 protein amount peaked 1 hr after ECS. MK P-1 induced did not lower the basal level of MAPK activity or attenuat e MAPK activation by second ECS. MAPK activation in cerebellum was ver y weak, but the MKP-1 induction was faster and more prominent than in the cortex. These results suggest that ECS induces MKP-1 in various ra t brain regions, however, the induction may not be related to the acti vation of MAPK and the MKP-1 induced may be independent of the regulat ion of MAPK( activity after ECS. (C) 1998 Academic Press.