Rapid dark-adaptation in the frog cone

Abstract

The aspartate-isolated late receptor potential was studied in the excised, perfused, bullfrog retina. A method was described whereby the late receptor potential of the cones could be monitored without interference from the response of the rods. It was shown that bullfrog cones are capable of rapid dark adaptation and that the process is substantially faster than it is in bullfrog rods. The shapes of the spectral sensitivity curves obtained in this and a previous study were discussed. It was suggested that cones may change their spectral response characteristics depending upon their state of adaptation.