5-HT1A RECEPTORS ARE NOT INVOLVED IN CLOZAPINES LACK OF CATALEPTOGENIC POTENTIAL

Clozapine and 8-OH-DPAT antagonized haloperidol-induced catalepsy in r ats (ED(50) 10 and 0.1 mg/kg s.c., respectively). Whereas the selectiv e 5-HT1A receptor antagonist WAY 100635 (0.1 mg/kg s.c.) completely an tagonized the inhibitory effect of 8-OH-DPAT, clozapine's effect was n ot affected. On the other hand, clozapine and 8-OH-DPAT inhibited ultr asonic vocalization in rats (ED(50) 0.7 and 0.03 mg/kg s.c., respectiv ely), which effects were antagonized by WAY 100635. The lack of catale psy of clozapine, therefore, cannot be addressed primarily to clozapin e's agonistic activity at 5-HT1A receptors. Copyright (C) 1996 Elsevie r Science Ltd.