Figure 2.
Isolated bleached salamander rods recover sensitivity faster after substantial bleaching of the visual pigment when exogenously treated with 11-cis 4-OH retinal compared with when treated with 11-cis-retinal. (A) The graph plots the time course of sensitivity changes (l1/2) in a rod during darkness before and after a bleach, after subsequent treatment with 10 µM 11-cis-retinal in 0.1% ethanolic solution. At 120 min, the rod was then exposed to a second bleach and finally, 80 min later, treated with 10 µM 11-cis 4-OH retinal in 0.1% ethanolic solution. (B) Recovery of sensitivity measured in single isolated rods treated as in A. The mean fitted time constant for recovery of sensitivity after treatment with 11-cis 4-OH retinal was 26.0 min; n = 9. Data points are plotted ± SEM. Because of the large variability, we were unable to obtain a reliable fit for the recovery of sensitivity after treatment with 11-cis-retinal. However, the mean time constant for recovery was considerably longer that the 26 min found for the 4-OH retinal.