Fig. 4

Long-term immune suppression impairs photoreceptor regeneration. (A) Scheme of experimental outline. opn1sw1:GFP transgenic animals (labeling UV-cones) were treated with Dexamethasone (Dex) or vehicle (Methanol; MeOH) from 10 days prior to lesion until the day of analysis (28 days post lesion; dpl; 38 days post treatment; dpt). EdU pulses were applied at 2, 4, 6, 8, 10, and 12 dpl. (B) In comparison to MeOH-treated animals, the number of regenerated EdU+ UV-cones is significantly reduced after Dex-treatment (compare upper panel with lower panel). Furthermore, the morphology of photoreceptor cells is disrupted in comparison to MeOH controls (arrowheads). (C) Quantification of EdU+ cells with respect to retinal layers show significant reduction of EdU positive nuclei in the Dex-treated group. Scale bars: 50µm, insets 10 µm. Error bars indicate SEM; * = p ≤ 0.05; ** = p ≤ 0.01; *** = p < 0.001; N ≥ 6; two-tailed t-Test. ONL = outer nuclear layer; INL = inner nuclear layer; GCL = ganglion cell layer.