DOPAMINE D2 RECEPTOR BLOCKADE ALTERS THE PRIMARY AND COGNITIVE COMPONENTS OF VISUAL-EVOKED POTENTIALS IN THE MONKEY, MACACA-FASCICULARIS

The effects of sulpiride, a dopamine D2 receptor antagonist, were stud ied on visual event-related potentials in a monkey performing in a vis ual oddball task in order to investigate receptor specific mechanisms in visuo-cognitive processes. Following the injection of 0.35 mg/kg su lpiride i.m., the amplitude and latency of the primary (P100) and cogn itive (P300) components did not change significantly. When 1.05 mg/kg sulpiride was administered, the latency of the primary and cognitive c omponents increased. The amplitude of the P100 component decreased, wh ile that of the P300 component increased. These data suggest that D2 r eceptors play an important role in visuo-cognitive processes in both p hysiological and pathological conditions such as Parkinson's disease a nd schizophrenia. (C) 1997 Elsevier Science Ireland Ltd.