SEEING THE DIFFERENCE: HOW BEHAVIORAL TEST CHOICE SHAPES VISUAL ASSESSMENT IN RD10 MICE

The retinal degeneration 10 (rd10) mouse is a commonly used animal model for retinitis pigmentosa, a group of inherited retinal disorders characterized by progressive vision loss. These mice carry a spontaneous mutation in the rod phosphodiesterase (PDE) gene, leading to photoreceptor degeneration in the retina beginning around postnatal day 18. Due to its relatively slow rate of degeneration compared to other models, rd10 has become a preferred model for studying retinitis pigmentosa. Nevertheless, behavioral experiments used to assess visual impairment must be carefully adapted to this model.
The aim of the present study was to characterize photoreceptor degeneration and the associated decline in visual function in the rd10 mouse model under different behavioral experimental conditions, such as the commonly used optomotor test or newly established tests, such as an adapted version of the Morris Water Maze (MWM) and the looming task. The focus was on age- and sex related differences as well as different light conditions.
Compared to the normal visual performance of C57BL/6 mice, our results demonstrate that the pronounced visual deficits observed in rd10 mice are strongly influenced by both the sex and light conditions in the MWM, whereas no sex related differences can be observed at the looming task, also at different ages.
Taken together, these findings indicate that the selection of animal sex in combination with the behavioral task is a critical factor when using this rd10 mouse model, even though vision itself could be assumed to be unrelated to sex.