Effects of fencamfamine on latent inhibition

The effects of fencamfamine (FCF), all indirect dopamine (DA) agent, were investigated using the latent inhibition (LI) model of schizophrenia. In the LI procedure, rats preexposed (PE) to an unreinforced stimulus show difficulty in subsequent learning of all association in which that stimulus is predictive of all unconditioned stimulus (US). FCF (1.75, 3.5 and 7.0 mg/kg ip) yielded an inverse dose-response relationship regarding LI, At 3.5 mg/kg, LI was abolished and no effect was observed at 1.75 and 7.0 mg/kg, The effect of FCF (3.5 mg/kg) on LI was blocked by the antipsychotic risperidone (RIS: 4.0 mg/kg), a D-2/5HT(2) antagonist. These results confirm the similarity of the behavioral profile of FCF and amphetamine (AMPH). In addition. they provide a further validation of the LI model for psychosis, since RIS was shown to prevent a psychostimulant-induced disruption of LI. (C) 2002 Elsevier Science Inc. All rights reserved.