Slight Alteration of the Electroretinogram in Mice Lacking Dystrophin Dp71

Abstract

Aim: Most Duchenne muscular dystrophy patients and the mdx^Cv3 mouse strain, lacking expression of both dystrophins Dp260 and Dp71, show a high attenuation of the dark-adapted electroretinogram (ERG) b-wave amplitude, whereas mice lacking the expression of Dp260 show normal b-wave amplitude. Here, we completed our assessment of whether the sole absence of Dp71 affects the ERG. Methods: Ganzfeld ERGs were performed on dark-adapted Dp71-null mice and littermates. Scotopic flash ERGs were recorded at light intensities from 3.10−⁵ to 1 cd.s/m². Oscillatory potentials (OPs) were extracted at 1 cd.s/m². Photopic flash ERGs were recorded at 10 cd.s/m² after light adaptation. Results: Dp71-null mice showed a slight but significant reduction in b-wave amplitudes, normal a-wave amplitudes and nonaffected implicit times of the scotopic ERGs. No changes were observed in the amplitudes and implicit times of the OPs and the photopic ERGs. Conclusions: Our results demonstrate that together both Dp71 and Dp260 are required for the generation of the ERG b-wave in mice.