Effects of zotepine, haloperidol and clozapine on MK-801-induced stereotypy and locomotion in rats.

In the present study we compared the effects of the atypical neuroleptic zotepine to haloperidol and clozapine on stereotypies and locomotion induced in rats by the N-methyl-D-aspartate (NMDA) antagonist MK-801. Zotepine caused a dose-dependent reduction of MK-801-induced stereotypies and locomotion. Zotepine at a dosis of 2.5 mg/kg body weight showed a similar effect to 0.25 mg/kg haloperidol in reducing stereotypies and locomotion. Clozapine (5.0 mg/kg) reduced significantly locomotion and non-significantly stereotypies. These results add support to the assumption that MK-801-induced behavior provides an adequate animal model to test the potential efficacy of typical and atypical neuroleptics in the treatment of psychoses.