DIFFERENT MODIFICATIONS OF THE DOPAMINE METABOLISM IN THE CORE AND SHELL PARTS OF THE NUCLEUS-ACCUMBENS FOLLOWING CCK-A RECEPTOR STIMULATION IN THE SHELL REGION

After the injection of CCK8 into the posterior N. Acc. of rats, DA, DO PAC and HVA contents were determined from punches of the anterior and posterior N. Acc. and VTA. CCK8 (20 pmol/side) modified these levels o nly in the posterior N. Acc. and these responses were inhibited by the CCK-A antagonist devazepide. Five min after treatment, DA, DOPAC and HVA were increased in the N. Acc.(shell) and 10 min later they were de creased in the N. Acc.(core). These data suggest that in these regions CCK8 could both abolish the influence of DA from the core on the tran smission of motor information and favor that of DA from the shell on e motional-like responses.