Haloperidol antagonism of amphetamine-induced effects on event-related slow potentials from rat cortex

Slow potential (SP) responses to a click followed after 2 sec by rewarding stimulation of the medial forebrain bundle were recorded from the frontal cortex of rats with permanently implanted electrodes. The SP responses were frequently enhanced by haloperidol (0.0125 to 0.1 mg/kg). Both haloperidol and alpha-methyltyrosine antagonized amphetamine-induced suppression of the SP responses. The results are consistent with the idea that dopamine (and possibly norepinephrine) exerts an inhibitory influence on the mechanisms involved in generation of event-related slow potentials.