Dialysis of NADPH-free solution into rods before a 50% bleach of the visual pigment. (A) Changes in log sensitivity after pigment bleaching plotted as a function of time. Sensitivity before (upward filled triangle) dialysis with internal solution containing 0 mM NADPH (black bar) is plotted (mean ± SEM). A 50% bleach is given at time 0 s. Recovery of sensitivity at the base of the outer segment commenced with a time constant of ∼290 s, and at the tip of the outer segment of ∼930 s. (B) Suction electrode configuration while dialyzing solution free of NADPH into the rod inner segment. On the bottom, responses to saturating flashes at selected time points during recovery in A are shown. (C) Dim flash responses in the dark-adapted cell after dialysis (gray) and at steady-state after pigment bleaching (black) indicating the response speeding characteristic of bleaching adaptation.