THE EFFECTS OF RACLOPRIDE ON VACUOUS JAW MOVEMENTS IN RATS FOLLOWING ACUTE ADMINISTRATION

Classic neuroleptics produce a syndrome of vacuous jaw movements in ra ts, whereas atypical neuroleptics like clozapine do not. The present s tudy compared the effects of repeated administration of raclopride, cl ozapine, haloperidol, or vehicle on vacuous jaw movements in rats over a 4-week period. Rats received an IP injection of drug once a day. On days 1, 8, 15, and 29 the rats were observed for a 5-min period by tw o trained observers who recorded their vacuous jaw movements. The dose -response curves at which each drug produced vacuous jaw movements are presented and discussed in terms of their predictive capabilities of early onset extrapyramidal side effects.