GUSTATORY THALAMUS LESIONS IN THE RAT .3. SIMULTANEOUS CONTRAST AND AUTOSHAPING

The performance of rats with electrophysiologically guided electrolyti c lesions of the gustatory thalamus (GT) was compared to that of contr ol subjects in two experiments. In Experiment 1, the lesioned rats sho wed normal simultaneous contrast effects (both positive and negative) during brief, alternating access to 0.15% saccharin and 1.0 M sucrose. There was, however, a substantial lesion-induced impairment in the le vel of conditioned stimulus-directed maintenance responding on the aut oshaping procedure of Experiment 2. These findings are discussed with respect to the anticipatory contrast deficit recently reported in GT-l esioned rats. (C) 1997 Elsevier Science Inc.