ELECTROCONVULSIVE SHOCK REDUCES THE CATALEPTOGENIC EFFECT OF BOTH HALOPERIDOL AND ARECOLINE IN RATS

The cataleptic response of rats following haloperidol administration (1.5 mg kg-1 i.p.) was measured at various times after a single electroconvulsive shock (ECS × 1), a single ECS daily for 5 days (ECS × 5). a single ECS daily for 10 days (ECS × 10) or 24 hr after a single sub-convulsive shock daily for 10 days (sub-con × 10). The cataleptic response following injection of haloperidol was markedly attenuated 24 hr but not 48 hr after ECS × 1, up to 48 hr after ECS × 5 and 72 hr but not 168 hr (7 days) after ECS × 10. Sub-convulsive shock × 10 did not alter the normal catalepsy response. Attenuation was also not seen 12 hr after ECS × 1. The possible involvement of GABA in these changes is discussed. A reduction in the cataleptic response to the cholinomimetic drug arecoline was also seen following ECS × 1 and ECS × 10 and such changes appeared to have a similar time-course to those seen in neuroleptic-induced catalepsy. Thus, ECS produces changes in these cataleptic responses which can be seen after a single shock and are consolidated and sustained following further treatment. The relevance of these findings to the enhanced monoamine behavioural responses seen in rats after ECS, and the possible relevance of the data to therapeutic mechanism of electroconvulsive therapy (ECT) are discussed. © 1979.