The effect of temperature on rapid dark adaptation in bullfrog photoreceptors—A difference between rods and cones

Abstract

The late receptor potential of the perfused bullfrog retina was isolated with sodium-aspartate. Rapid dark adaptation of the rods and of the cones was monitored independently of one another. In rods, decreasing the temperature both increased the latency of onset of rapid dark adaptation and decreased the rate of adaptation following onset. In cones, only the latency of onset of adaptation was found to be temperature dependent. We conclude that both the latency and recovery phases of the adaptation are enzymatically mediated in rods, but that in cones the actual recovery phase is dependent mainly on diffusion. The mechanistic basis of these observations is discussed.