Disruption and potentiation of latent inhibition by XXXX : the latent inhibition model of atypical antipsychotic action.

@entity1 @entity1088 @entity9178 @entity161 @entity1767 @entity952 @entity35 @entity4944 @entity734 @entity1090
@entity9178 ( @entity9178 ), that is, retarded conditioning to a stimulus following its nonreinforced pre-exposure, is impaired in some subsets of @entity161 @entity1 and in @entity4944 -treated @entity35 . Potentiation of @entity9178 by @entity734 ( @entity734 ) given in conditioning, under conditions that do not lead to @entity9178 in controls, is a well-established index of antipsychotic activity. Recently, we have shown that the atypical APD, @entity1088 , in addition disrupts @entity9178 if administered in pre-exposure, under conditions that lead to @entity9178 in controls. This study demonstrates the same behavioral profile for the atypical APD @entity1090 . @entity9178 was measured in a thirst-motivated conditioned emotional response procedure by comparing suppression of drinking in response to a tone previously paired with a foot shock in @entity35 that received nonreinforced exposure to the tone prior to conditioning (pre-exposed (PE)) and @entity35 for whom the tone was novel (non-pre-exposed (NPE)). We show that under conditions that did not yield @entity9178 in vehicle controls (40 pre-exposures and five conditioning trials), @entity1090 (0.25, 0.5, and 1.2 mg/kg) led to @entity9178 when administered in conditioning. Under conditions that led to @entity9178 in vehicle controls (40 pre-exposures and two conditioning trials), @entity1090 (0.25, 0.5, and 2.5 mg/kg) abolished @entity9178 when administered in pre-exposure; the latter effect was not evident with @entity1767 . In addition, the effects of @entity1090 administered in both the pre-exposure and conditioning stages were dose-dependent so that the pre-exposure-based action was manifested at lower but not at higher doses. It is concluded that atypical @entity734 exert in the @entity9178 model a dual pattern of effects, which enables detection of their 'typical' action (conditioning-based @entity9178 potentiation) as well as a dissociation from typical @entity734 by their 'atypical' action (pre-exposure-based @entity952 ). It is suggested that the former and latter effects are subserved by D2 and 5HT2A antagonism, respectively.
