Spectral interactions in horizontal and ganglion cells of the isolated and arterially-perfused rabbit retina

Abstract

Intracellular and extracellular recordings in the arterially-perfused eye cup of pigmented and albino rabbits show the presence of blue cones, green cones and rods. Among the ganglion cells, a fraction shows spectral opponency. Two main types were found. In one, on-depolarizing responses and on-hyperpolarizing responses receive antagonistic input from different cone types ('B/G'); in the other, on-depolarizing responses receive input from both blue and green cones wheras off-depolarizing responses receive input either from blue or from green cones ('BG/G','BG/B'). Two types of horizontal cell responses have been found, both receiving mixed green cone and rod input; one type is cone-dominated while the other is rod-dominated. Neither type shows C-type responses or obvious input from blue cones, either synergistic or antagonistic, with intense selective chromatic adaptation of green cones and rods. Mass b-wave responses show a spectral sensitivity suggestive of antagonistic interactions between blue and green cones signals to inner nuclear layer neurones, which were not seen in action spectra based on a-wave or PIII component responses. It is argued that although blue cone signals contribute to spectral interactions at the ganglion cell and inner nuclear layer cell levels, they do not seem to contribute significantly to such interactions at the receptor or horizontal cell levels.