Fig. 8

Unilateral TNFα injection induces visual defect, inflammation, and p-p38 pathway activation in both SCs. a Diagram showing the neuronal visual pathway in rodent. TNFα (25 ng/μl) is injected into the right SC. b The optomotor set-up allowed the determination of the optokinetic tracking threshold measurements (cycles per degree) for the left and right eyes, independently scored (clockwise and counterclockwise responses, respectively) under photopic conditions. Right and left eye sensitivity for naïve (n = 5), left (n = 6), and right (n = 6) rats at 5, 7, 9, and 15 days after TNFα injection. RT-qPCR analysis for GFAP (c), CD68 (d), and IL-1β (e) mRNA levels in naïve, left, and right SCs. For each marker, mRNA levels are presented as a fold change relative to naïve rats after normalization with respect to the housekeeping gene (GAPDH). Each bar is the mean ± SEM. n = 8–10 animals/group. Immunofluorescence of GFAP, Iba1/CD68, and Iba1/p-p38 (f) in naïve, left, and right SCs. Arrows show colocalization between markers. Scale bar = 200 μm (GFAP) and 50 μm (Iba1/CD68 and Iba1/p-p38). Quantification of Iba1⁺CD68⁺ cells (g) and Iba1 + p-p38+ cells (h) in naïve (n = 5), left (n = 6), and right (n = 6) SCs. Results are expressed in arbitrary units and correspond to the means ± SEM. Two-way ANOVA for repeated measures followed by Bonferroni post hoc test was used for optomotor responses: *p < 0.05, **p < 0.01, and ***p < 0.001 naïve, right, and left eyes. We performed a one-way ANOVA followed by the Dunnett multiple comparisons test: **p < 0.01, ***p < 0.001, and ****p < 0.0001 and the Kruskal–Wallis test for IL-1β