THE EFFECTS OF DOPAMINE BLOCKADE ON THE HUMAN FLASH ELECTRORETINOGRAM

Single-cell electrophysiologic studies have shown that dopamine modula tes retinal activity, but its role in human retinal processing is uncl ear. We investigated the effects of short-term oral administration of dopaminergic receptor blocking agents on the flash electroretinogram i n humans. Both chlorpromazine (25 and 50 mg) and fluphenazine (1 and 2 mg) significantly reduced electroretinogram b-wave amplitudes and als o selectively reduced the amplitude of the first oscillatory potential . Implicit times were not altered. Metoclopramide (10 and 20 mg) had n o effect on any electroretinographic variable. Our study indicates tha t dopamine receptor blocking agents with both D-1 and D-2 receptor aff inities reduce the amplitude of the electroretinogram in humans.