Evidences for a direct action in striatum of dopaminergic receptor antagonists mediating DOPAC formation

DOPAC changes elicited by dopaminergic receptor antagonists have been investigated either by local application of trifluoperazine in striatum or substantia nigra. The results seem to suggest that the mechanisms responsible for DOPAC formation are localized outside the substantia nigra and possibly intrinsic to the striatum. Cholinergic neurons seem to partially regulate the haloperidol-induced increase of striatal DOPAC. Moreover, cortical ablation indicates that this effect is not mediated by the interaction of dopaminergic antagonists with the population of receptors located on corticostriatal pathways.