Alteration of monkey retinal oscillatory potentials after MPTP injection.

We have investigated the functional role of dopamine in the monkey retina by recording the retinal responses to flash stimulations before and after destruction of dopaminergic cells by intravenous injection of N-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP). We evaluated specifically the oscillatory potentials (100 Hz-3 KHz) of the electroretinogram. By day 47 after MPTP injection, a selective decrease of the amplitude of the first oscillatory potential was observed. At that time the animals had been receiving antiparkinsonian therapy since day 15. These results suggest that retinal dopaminergic neurons may play a role in the generation of the first oscillatory potential, and moreover, that each oscillatory potential should be considered individually.