Fig. 8.

Bleaching adaptation supports recovery of contrast sensitivity at high irradiance. a Experimental protocol. Ganglion cell responses in Cnga3 ^−/− retinas were tested at high light levels (10⁵ R* rod⁻¹ s⁻¹), with brief (10 min) interruptions with dim light (10² R* rod⁻¹ s⁻¹). During the last three dim segments, 50 µM 9-cis retinal was applied. b–d Relative response strength of one example ganglion cell to 2-s positive and negative contrast steps (same stimulus as in Fig. 2b), during one experimental segment at 10⁵ R* rod⁻¹ s⁻¹ after 9-cis retinal application. b Spike raster. c Average firing rate to the last 50 repetitions of the stimulus (top) was used as a template to quantify the evolution of response strength in this experimental segment by linearly fitting the first 1000 ms of the cell’s response (average firing rate to five stimulus repetitions) after each contrast transition (ON stimuli of low and high contrast, light red and red; OFF stimuli of low and high contrast, light blue and blue). d Evolution of response strength of this cell during this experimental segment, for all four contrast transitions. e, f Median relative response strength (e) and cumulative distribution of relative response strength (f, for the first eight time points shown in e) across all experimental segments and all ganglion cells from four retinas recorded with an experimental protocol as in a, and two retinas recorded with a similar protocol without supplying 9-cis retinal. Test for statistical significance was performed with a permutation test (Methods). Note that the relative response strength can be <0 and >1 (see examples in c, d), so that the cumulative distribution does not fully cover the range from 0 to 100% in the panels shown in f