Steinpreis R E, Kaczmarek H J, Harrington A
Department of Psychology, University of Wisconsin-Milwaukee 53211, USA.
Physiol Behav. 1996 Jul;60(1):253-6. doi: 10.1016/0031-9384(96)00022-4.
Classic neuroleptics produce a syndrome of vacuous jaw movements in rats, whereas atypical neuroleptics like clozapine do not. The present study compared the effects of repeated administration of raclopride, clozapine, 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 two 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.