Rod saturation in b-wave of the rat electroretinogram under two different anesthetics.

B-wave increment threshold experiments in the rat show that "rod saturation" occurs at different background levels with different anesthetics. Rod saturation builds up over the first 60 sec of light adaptation in pentobarbital anesthetized but not in urethane anesthetized animals. These and other findings suggest that "rod saturation" can occur when the rod photoreceptors themselves are not saturated.