Effects of discrimination learning on the rat striatal dopaminergic activity

Abstract
THE prefrontal cortex (PFC) has anatomical and functional relationships with the striatum. In a previous study we showed that dopamine (DA) turnover in the PFC of rats is enhanced during the performance of a discrimination task. In the present study, we used an in vivo microdialysis method to examine whether DAergic activity in the striatum could also be altered by the discrimination task. The results showed a substantial and sustained suppression of DAergic activity during and after the discriminative behaviour. The fact that thediscriminative performance induced opposite changes in DAergic activity in the striatum and the PFC is consistent with the results of biochemical studies, suggesting that the suppressed DA turnover in the striatum may be induced by the enhanced DAergic activity in the PFC during the discrimination task.