3,4‐DIHYDROXYPHENYLACETIC ACID (DOPAC) AND THE RAT MESOLIMBIC DOPAMINERGIC PATHWAY: DRUG EFFECTS AND EVIDENCE FOR SOMATODENDRITIC MECHANISMS

Abstract

Drug effects on dopamine catabolism of the mesolimbic dopaminergic pathway have been investigated using a sensitive radioenzymatic assay for 3,4‐dihydroxyphenylacetic acid (DOPAC). Turnover of DOPAC was less rapid in the ventral tegmentum (containing somata and dendrites) than in the nucleus accumbens (containing nerve terminals): 9 and 115 ng g−1 min−1 for ventral tegmentum and nucleus accumbens respectively. Reserpine (5 mg/kg, 1 h) elevated DOPAC concentration to a greater extent in ventral tegmentum than in nucleus accumbens. Neuroleptic drugs elevated DOPAC levels in ventral tegmentum and nucleus accumbens. Thioridazine, sulpiride and clozapine, thought to act preferentially on the meso..