Differences in dopamine release and metabolism in rat striatal subregions following acute clozapine using in vivo microdialysis

This study examined and compared the effects of acute clozapine administration over a range of doses on the release of dopamine (DA) and its metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) in dorsolateral and fundus striata. Basal extracellular DA levels were significantly higher in the dorsolateral striatum. However, DOPAC levels were similar in both regions. Acute treatment with clozapine (40 mg/kg) was associated with an increase in extracellular dopamine in the dorsolateral striatum but not in the fundus. In contrast, an increase in extracellular DOPAC was seen in both regions following all doses of the drug; however, clozapine was more potent in the dorsolateral striatum than in the fundus. These results illustrate the functional heterogeneity of the striatum and in addition, indicate a possible dissociation between the effect of acute clozapine on DA release and DA metabolism.