Both the shell of the nucleus accumbens and the central nucleus of the amygdala support amphetamine self-administration in rats.

Intracranial self-administration of drugs offers the opportunity to localize the neuronal substrates mediating the rewarding effects of drugs. The purpose of the present study was to explore whether the nucleus accumbens shell and the central nucleus of the amygdala, two components of the "extended amygdala," would support self-administration of the psychostimulant amphetamine. Male Wistar rats were trained to lever press under a Fixed Ratio 1 schedule of reinforcement for D-amphetamine injections (0, 1.0, 1.5, 2.0 and 3.0 microg/microl/inj) into either the nucleus accumbens shell or the central nucleus of the amygdala. An ascending limb dose-response function with peak responding at the 2.0 microg/microl/inj dose was obtained for self-administration at both brain sites. These results indicate that monoaminergic transmission in both the nucleus accumbens shell and the central nucleus of the amygdala mediates the rewarding effects of amphetamine. Further, the present study provides additional evidence about the functional homogeneity of the forebrain continuum called the "extended amygdala."