Figure 8.

Effect of environmental light conditions on retinal microglia and macroglia. (A–H) Representative images of retinal sections from a C57BL/6J mice maintained at 50 lux cyclic light (A, E) and rd10 mice reared at 5 (B, F), 50 (C, G), and 300 lux (D, H) cyclic light, immunolabeled against Iba1 (microglia, red) and CD68 (phagocytic vesicles, green). CD68 immunolabeling revealed a light-dependent increase in phagocytic activity of microglial cells in rd10 mice (F–H). Insets show a magnification of representative microglial cells. (I–N) Representative cross-sectional retinal cryosections showing GFAP immunostaining (activated macroglia, green) and their corresponding profile plots of mean gray intensity from C57BL/6J mice (I–K) and rd10 mice (L–N) reared at 5, 50, and 300 lux. GFAP immunolabeling showed a light-dependent increase in reactive gliosis in rd10 mice (L–N). (O–Q) Quantification of the number of Iba1⁺ cells (O) and CD68⁺ cells (P) per section from each experimental group and the CD68⁺/Iba1⁺ ratio (Q) for rd10 mice (n = 4 to 6). (R) Quantification of GFAP immunofluorescence relativized to the retinal area for each experimental group (n = 3). Kruskal–Wallis and Dunn's post-hoc test. ^*P < 0.05. ONL, outer nuclear layer; OPL, outer plexiform layer; INL, inner nuclear layer; IPL, inner plexiform layer. Scale bar: 20 µm.