THE ATYPICAL ANTIPSYCHOTIC, REMOXIPRIDE, BLOCKS PHENCYCLIDINE-INDUCED DISRUPTION OF PREPULSE INHIBITION IN THE RAT

The effect of various typical (haIoperidol) and atypical (clozapine, raclopride, remoxipride) antipsychotics on phencyclidine (PCP)-induced disruption ofsensorimotor gating was tested in rats using an acoustic startle paradigm. Clozapine (4-40 mu mol/kg), haloperidol (1-5 mu mol/kg) and raclopride (1-12 mu mol/kg) failed to reverse PCP-induced disruption of prepulse inhibition (PPI) of the acoustic startle response. In contrast, remoxipride (12-60 mu mol/kg) caused a dose-dependent block of this effect. PCP-induced disruption of PPI is a widely accepted animal model of a corresponding behavioural deficit observed in schizophrenia although little evidence has been presented that it is in fact sensitive to antipsychotic agents. The present results indicate that remoxipride behaves in a unique way in this model compared to clozapine, haloperidol and raclopride.