Prelimbic cortex specific lesions disrupt delayed-variable response tasks in the rat.

The role of the prelimbic cortex (PL) in rats was investigated with excitotoxic lesions. PL lesions altered the alternation scores in spontaneous and reinforced spatial delayed-alternation tasks. PL lesions induced a delay in conditioning under a temporal go/no-go alternation schedule but not under a continuous food-reinforcement schedule in a runway. PL lesions had no effect on the acquisition of a standard radial-arm-maze task nor on a fixed-goal location task but disrupted the acquisition of a variable-goal location task in a radial-arm maze. The present 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 unaffected fixed-response tasks. These results are discussed in relation with a working-memory, a response-selection, and an attentional hypothesis.