Studies in retinas at stages extended from normal development show reduction of R-BPC number occurs with aging in the Atoh7−/− retina.

A–H. Confocal images of Atoh7−/− retinas displaying a normal R-BPC (red nuclei with green soma & processes) number at 1-month old (1 M); and progressive reduction of R-BPC numbers at 2 M, 3 M, and 8 M. R-BPCs maintain a constant number through all examined stages in wildtype retinas. The number of C-BPCs (red nuclei without green soma) in the Atoh7−/− retina is apparently reduced compared to the wildtype at 1-month, but the number remains unchanged with age. Red: Chx10; green: PKCα; blue: Topro3. Scale bar  = 50 µm. I–K. Histograms of R-BPC and C-BPC estimates indicating the number of R-BPCs, but not C-BPCs, are reduced with age.