Reward-related signaling in the dorsal striatum

BELLUSCIO MA; MURER MG; MARTINEZ MC

buenos aires

Congreso; XXXII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencia; 2017

Sociedad Argentina de Investigación en Neurociencia

The ability to predict rewarding outcomes is essential for learning and consolidating stimulusrewardassociations. The striatum is part of the basal ganglia and it is involved not only in themotor control of a sequence of actions but also in coding other aspects related to a task suchas cues that are associated to a reward, estimation of time, reward-prediction error, etc.Here we used tetrodes to record striatal activity in a self-initiated rewarded task. Briefly, aftera minimum inter-trial interval of 2.5 s, water-deprived rats must enter a nosepoke and,following a visual cue, emit an eight-licks sequence onto a tube to receive water.Behavioral analysis shows that subjects quickly learn to perform lick sequences but havemore difficulties in the control of their timely emission, as they prematurely enter thenosepoke. Premature entries reset the timer, reducing the reward rate, but with traininganimals learn the action-outcome association, improving their performance in the task.In electrophysiological records we found bracketing-like activity in beginning and the endingof the trials and also activity related to the visual cue and the delivery of the reward.Interestingly, we found neuronal activity modulation that correlates with the length of the ITI,both for correct trials and premature entries with sequences. These findings show that thestriatum is coding multiple aspects of the task.