Figure 1.

Maximum b-wave amplitude of dark-adapted ERG responses in (A) Nrl^−/− and (B) Nrl^−/−Grk1^−/− mice. Mice were dark adapted overnight before ERG recordings. Maximum responses were elicited by high-intensity white fluorescent light. Note the rapid decrease of b-wave amplitude (approximately 40% from 1 to 3 months) with increasing age in the Nrl^−/−Grk1^−/− mouse reared in the dark, in cyclic light, or in constant light.