Differential contributions of the basolateral and central amygdala in the acquisition and expression of conditioned relapse to cocaine-seeking behavior.

The amygdala is known to be a critical mediator of emotional learning in aversive and appetitive conditioning. Here we show for the first time that distinct subregions of the amygdala play unique roles in the acquisition and expression of cocaine-seeking behavior maintained by drug-paired cues in a model of relapse. Reversible inactivation of the basolateral amygdala with the sodium channel blocker tetrodotoxin disrupted both the acquisition and expression of the conditioned reinforcing effects maintained by drug-paired stimuli. However, inactivation of the central amygdala disrupted only the expression, but not the acquisition, of the conditioned reinforcing effects of drug-paired stimuli. Our results demonstrate that these nuclei participate as components of an amygdalar circuit to drive cocaine-seeking behavior produced by stimulus-reinforcement associations.