(D) Average ± SE (n = 5) scotopic a-wave amplitudes, representing photoreceptor function, for RanBP2+/− and RanBP2+/+ mice in response to bright flashes. Amplitudes of responses from RanBP2+/− mice were lower over the entire range of stimulus intensities for both b- and a-waves. Asterisks represent significant differences between the groups (Student's t test, p < 0.05). Statistical significance was found across all intensities for b-wave amplitudes (2-way ANOVA, p < 0.0001), but not for the a-wave.