A, B) ERGs recorded from 4 weeks old WT RA, WT OIR, and A2−/− OIR mice at intensities of 7 cd/m2 (candela per square meter) and 13 cd/m2 respectively. The data show averages of responses over both eyes, in 9, 6, and 16 WT RA, WT OIR, and A2−/− OIR mice, respectively. C) Mean b-wave amplitudes for WT RA, WT OIR, and A2−/− OIR mice are plotted against intensity. Responses are represented as mean ± SEM of the b-wave amplitudes, measured from the trough of the a-wave to the peak of the b-wave. Asterisks indicate significant differences between the two WT and A2−/− OIR groups (P<0.05, t-test). WT RA responses were significantly larger compared to both OIR groups at all intensities studied. Sample size varies from 6–16. * A2−/− OIR vs WT OIR (P<0.05).