Figure 1. Per2^luc mice show a significant reduction in the photoreceptor layer thickness during aging.

Measurement of in vivo retinal thickness in both C57BL/6J and Per2^luc mice revealed no differences in total retinal thickness in the young (A; p > 0.05, t-tests; n=5-6). When we measure the thickness of the different retinal layers, a small difference was observed in the NFL-GCL and in the INL (C; p > 0.05, two-way ANOVA, Tukey post-hoc, n=5-6) at 3 months of age. However, at 12 months of age, there was a significant decrease in the total retinal thickness in Per2^luc mice when compared to age matched C57BL/6J mice (B; *=p < 0.05, t-test, n=5-6). A small decrease in the thickness of INL was detected in older Per2^luc mice (D; *=p < 0.05, two-way ANOVA, Tukey post-hoc) and a much more pronounced reduction was observed in the photoreceptor layer (ONL and ISOS) was observed in aged Per2^luc mice (D; *=p < 0.05, two-way ANOVA, Tukey post-hoc). No significant differences were detected in the other retinal (p > 0.05, two-way ANOVA). NFL- Nerve fiber layer; GCL- Ganglionic cell layer; IPL-Inner Plexiform layer; OPL- Outer plexiform layer, ONL- Outer Plexiform layer, ISOS- Inner segment and outer segment (n=5-6 in all cases).