Ablation of CRH-1 amacrine cells dramatically alters the response profile of SbC RGCs to positive contrast. (A) DIC image of the pre-ablation retina overlayed with fluorescence of tdTomato labeled amacrine cells (red). Location of the recorded SbC RGC is pseudocolored in green and the control ON RGC in cyan. (B) DIC image of the post-ablation retina containing the SbC RGC filled with AlexaFluor 488 (green) and a spared tdTomato-positive amacrine cell (red, marked with white arrowhead). Scale bars are 50 μm. Cell-attached recordings from the SbC RGC (C) and control RGC (E) displaying the total number of spikes from baseline to positive and negative contrast. Traces are averages of 5–9 trials and error bars are s.e.m. Population data to positive contrast for SbC RGCs (D;
n = 5, 4, 5 in pre-ablation, post-ablation, and ablation + strychnine, respectively) and control RGCs (F;
n = 6 for both conditions) in the pre-ablation environment (black), post-ablation environment (red), or post-ablation in the presence of 1 μM strychnine (purple). Error bars are s.e.m. across cells. Each cell recorded was normalized to pre-ablation conditions.