PRELIMBIC CORTEX SPECIFIC LESIONS DISRUPT DELAYED-VARIABLE RESPONSE TASKS IN THE RAT

The role of the prelimbic cortex (PL) in rats was investigated with ex citotoxic lesions. PL lesions altered the alternation scores in sponta neous and reinforced spatial delayed-alternation tasks. PL lesions ind uced a delay in conditioning under a temporal go/no-go alternation sch edule but not under a continuous food-reinforcement schedule in a runw ay PL lesions had no effect on the acquisition of a standard radial-ar m-maze task nor on a fixed-goal location task but disrupted the acquis ition of a variable-goal location task in a radial-arm maze. The prese nt results indicate that PL lesions replicated most of the behavioral deficits obtained with larger prefrontal lesions. PL lesions disrupted the acquisition of delayed-variable response tasks while leaving unaf fected fixed-response tasks. These results am discussed in relation wi th a working-memory, a response-selection, and an attentional hypothes is.