Changes in nucleus accumbens core firing patterns during reward-related events

Learning is characterized by the ability to appropriately respond to external cues that predict rewarding or aversive outcomes. The nucleus accumbens is a key mediator of reward prediction and reward-related behaviors. However, it is not well understood how accumbens neurons acquire and maintain their responsiveness to these events. In the present study, 56 nucleus accumbens core neurons were electrophysiologically recorded over 10 sessions when the animals were trained in a conditioning paradigm. Changes in firing rates of core neurons were analyzed over training days during the following events: reward cue presentation, cued and non-cued approaches towards the reward, reward consumption and reward seeking. As a population, core neurons displayed an increase in firing rate in response to presentation of the reward predicting auditory cue. The latency of core activity in response to the auditory cue was significantly reduced after animals acquired the task. Increased firing rates were also observed during approach behaviors following the onset of cue, but notPh. D.Includes bibliographical referencesby Sisi M