THE ROLE OF MESOLIMBIC DOPAMINERGIC AND RETROHIPPOCAMPAL AFFERENTS TOTHE NUCLEUS-ACCUMBENS IN LATENT INHIBITION - IMPLICATIONS FOR SCHIZOPHRENIA

Latent inhibition (LI) consists in a retardation of conditioning seen when the to-be-conditioned stimulus is first presented a number of tim es without other consequence. Disruption of LI has been proposed as a possible model of the cognitive abnormality that underlies the positiv e psychotic symptoms of acute schizophrenia. We review here evidence i n support of the model, including experiments tending to show that: (1 ) disruption of LI is characteristic of acute, positively-symptomatic schizophrenia; (2) LI depends upon dopaminergic activity; (3) LI depen ds specifically upon dopamine release in n. accumbens; (4) LI depends upon the integrity of the hippocampal formation and the retrohippocamp al region reciprocally connected to the hippocampal formation; (5) the roles of n. accumbens and the hippocampal system in LI are interconne cted.