al., 2008) and the present study supports the idea that conditioning, learning and motor activity factors associated with operant ethanol self-administration play an important role in gene expression within the ACB. In addition, operant ethanol self-administration may be activating different neuronal circuits within the shell and core, producing changes in gene expression that are not observed by measuring the ACB-shell alone. These results also suggest that the number of ethanol drinking episodes, and the blood alcohol levels attained have a small impact on gene expression changes in the ACB-shell.
