Fig. 4

Minocycline ameliorates axonal degeneration and functional deficit in aquaporin-4 (AQP4)–immunoglobulin (IgG)-induced optic neuritis (ON) rats. A Experimental time course. B, D Left: Representative images of Iba1 staining(green). Scale bar: 50 μm. Right: Representative images of MPO staining (red). Scale bar: 50 μm. C, E Left: Quantification of Iba1-positive area (%) (AQP4-IgG + PBS: n = 6, AQP4-IgG + minocycline: n = 6, mean ± SEM ***p < 0.001, assessed by Student’s t test). Right: Quantification of MPO-positive area (%) (AQP4-IgG + PBS: n = 6, AQP4-IgG + minocycline: n = 6, mean ± SEM, ns means no significant difference, assessed by Student’s t test). F Experimental time course of the analysis on retinal ganglion cell (RGC) axon quantification. G Representative confocal images showing CTB-labeled axons in the longitudinal optic nerve section. White arrows indicate the injection site. Scale bar: 500 μm. H Representative images of CTB-labeled axons in transverse sections at 1 mm and 4 mm posterior to the IgG-injected site. Scale bar: 20 μm. I, J Quantification of CTB-labeled axons at 1 mm and 4 mm posterior to the IgG-injected site (AQP4-IgG+PBS: n = 5, AQP4-IgG+minocycline: n = 5, mean ± SEM, ***p < 0.001 assessed by Student’s t test). K Representative images of FluoroMyelin staining at 1 mm and 4 mm posterior to the IgG-injected site. L, M Quantification of FluoroMyelin-positive area at 1 mm and 4 mm posterior to the IgG-injected site (AQP4-IgG + PBS: n = 5, AQP4-IgG + minocycline: n = 5, mean ± SEM, **p < 0.01, assessed by Student’s t test). N Experimental time course of PLR experiment. O Quantification of pupillary constriction (%) (AQP4-IgG+PBS: n = 7, AQP4-IgG+minocycline: n = 7, mean ± SEM, **p < 0.001, ***p < 0.001, assessed by two-way ANOVA, followed by Bonferroni test). P Quantification of CTB-labeled axons at 4 mm posterior to the IgG-injected site. (AQP4-IgG+PBS: n = 7, AQP4-IgG+minocycline: n = 7, mean ± SEM, **p < 0.01 assessed by Student’s t test). Q Spearman's correlation coefficient test was used to assess the correlations between the number of CTB-positive axons (day 24) and constriction rate of Pupillary light reflex (day 21) (AQP4-IgG+PBS: n = 7, AQP4-IgG+minocycline: n = 7)