The electroretinographic change by the acute effects of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine

ABSTRACT

The electrophysiological effects of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (NMPTP), a chemical inducer of Parkinsonism in man and monkey, on the pigmented rabbit retina were determined under acute conditions. The amplitude of the b-wave of the rabbit electroretinogram was affected, but both the implirit time and half-amplitude duration of it werenot. The amplitude of the photopic b-wave was increased by 72.9 +/- 32.1% 5hours after the intravenous injection of NMPTP (P[t] < 0.05), whereas that of the scotopic b-wave was decreased by 31.2 +/- 6.4% 4hours after injection (P[t] < 0.05). The above results suggest or support that 1, the dopaminergic amacrine cells are related to the modulation of the b-wave of the rabbit electroretinogram. 2. during light adaptation, the dopaminergic amacrine cells uncouple the rod and cone systems in the inner plexiform layer and are involved in functions of the rod system. 3. the hypothesis that the funrtion of tyrosine hydroxylase may be affected by NMPTP.