Validation of the automated counting method. (a) Staining of cones with PNA in wild-type (wt) and in retinal degeneration (rd1) of flat-mounted retina at PN15, 35 and 90. (b) Average cone densities of rd1 and wt retinas using global automated counting method. (c) Average cone densities of rd1 and wt retinas using stereological counting on contralateral eyes. The data represents an average of at least seven retinas per age and per genotype. Error bars show +/- SEM, * p < 0.05, ** p < 0.01, *** p < 0.001. Scale bar: 100 μm.