ELECTROPHYSIOLOGICAL RESPONSES OF NUCLEUS-ACCUMBENS NEURONS TO NOVELTY STIMULI AND EXPLORATORY-BEHAVIOR IN THE AWAKE, UNRESTRAINED RAT

To establish a physiological correlate of goal-directed and reward-see king non-operant behaviors, we studied the electrophysiological activi ty of NAcc neurons in unrestrained, naive Sprague-Dawley rats. Our res ults showed an inhibitory response in 21% (7/34) of the recorded NAcc neurons during spontaneous nosepoking behavior and in 16% (4/25) of th e NAcc neurons when rats were fed with a favorite novel food morsel (p opcorn). These data suggest that a subgroup of NAcc neurons is activel y modulated during motivated behavior and during consummatory events r esulting in a suppression of neuronal activity. (C) 1998 Elsevier Scie nce B.V. All rights reserved.