Intracellular recordings from single rods and cones in the mudpuppy retina.

Mudpuppy rod and cone responses differ both in time course of recovery and in absolute sensitivity. Rods are about 25 times more sensitive than cones and appear to generate a larger voltage per quantum absorbed. Comparison of mudpuppy receptor sensitivities to those of other vertebrates suggests that the difference in sensitivity between rods and cones may be a general phenomenon.