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 studied on visual event-related potentials in a monkey performing in a visual oddball task in order to investigate receptor specific mechanisms in visuo-cognitive processes. Following the injection of 0.35 mg/kg sulpiride i.m., the amplitude and latency of the primary (P100) and cognitive (P300) components did not change significantly. When 1.05 mg/kg sulpiride was administered, the latency of the primary and cognitive components increased. The amplitude of the P100 component decreased, while that of the P300 component increased. These data suggest that D2 receptors play an important role in visuo-cognitive processes in both physiological and pathological conditions such as Parkinson's disease and schizophrenia. (C) 1997 Elsevier Science Ireland Ltd.