Predicting how equipotent doses of chlorpromazine, haloperidol, sulpiride,raclopride and clozapine reduce locomotor activity in mice

Distinguishing the specific effects of neuroleptics on one particular behav iour from its non-specific effects on motility is not easy. In this study, the effects of five neuroleptics on spontaneous motor activity were compare d and the ED50 values of these drugs to impair activity were calculated. Ma le and female mice were evaluated in an actimeter or in a shuttle-box used as an open field after the administration of chlorpromazine (0.4, 1.2. 3.6 mg/kg), haloperidol (0.1, 0.3, 0.9 mg/kg), raclopride (0.1, 0.3, 0.9 mg/kg) , sulpiride (10, 30, 90 mg/kg) and clozapine (0.4, 1.2, 3.6 mg/kg), and two automatic and two observational activity measures were obtained. A very hi gh correlation between automatic and observational measures, absence of sex differences, and a dose-dependent decrease of activity were observed with every compound. The results allow us to make accurate comparisons between t hese drugs in their potency in reducing spontaneous motor activity. (C) 200 0 Elsevier Science B.V. All rights reserved.