Collections > Electronic Theses and Dissertations > Cocaine Abstinence Alters Nucleus Accumbens Firing Dynamics During Goal-directed Behaviors for Cocaine and Sucrose

Distinct subsets of nucleus accumbens (NAc) neurons differentially encode goal-directed behaviors for natural versus drug rewards, and the encoding of cocaine-seeking is altered following cocaine abstinence. Here, electrophysiological recordings were made to determine if NAc selective encoding of natural versus cocaine reward is: (1) maintained when the natural reinforcer is highly palatable and (2) altered by cocaine abstinence. Rats (n=14) were trained on a sucrose/intravenous cocaine multiple schedule and NAc activity was recorded before and after 30 days cocaine abstinence. Before abstinence, the majority of NA neurons displayed nonoverlapping patterns of activity during the task. After abstinence, this pattern was largely maintained; however, more neurons became selectively activated during cocaine- versus- sucrose-seeking. The results indicate that although the selective encoding of cocaine and natural rewards is maintained even with a highly palatable substance, 30 days of cocaine abstinence dynamically alters overall population encoding of natural and drug rewards.