Figure 3.

Satiety signaling in nucleus accumbens neurons. A, Mean latency to lick after trial initiation increased over the course of the behavioral session as a function of the reinforcer received in the previous trial. Inset shows mean latency for each of the three reinforcers. B, Mean bout length devoted to consumption of each of the three sucrose reinforcers declined significantly over the behavioral session (all p < 0.05). C, In a typical palatability-modulated neuron, firing rate remained constant over the course of the behavioral session, even as mean lick bout length diminished significantly (all p < 0.05 for bout lengths; all p > 0.05 for spike rates; squares indicated bout lengths; circles indicate firing rates). D, In the entire population of palatability-modulated units, firing rate and bout length did not covary over the course of the behavioral session (r = 0.07; p > 0.05).