Fig. 4

Genetic ablation of Sarm1 attenuates cortical microgliosis and astroglial scar formation. (A-B) At 1 month after rTBI, there were significantly more Iba-1-stained microglia in the injured versus non-injured cortex in all groups (p = 0.045 for group effects, p = 0.001 for ROI effects, p = 0.299 for group x ROI interaction), whereby this effect was attenuated in both Sarm1^+/− (p = 0.028) and Sarm1^−/− (p = 0.034) mice. (C-D) We observed focal astrogliosis in the injured cortex of Sarm1^+/+ and Sarm1^−/−, but not Sarm1^+/−, mice. After exclusion of the glial scar from analysis, we found no difference in the GFAP-staining signal between hemispheres and groups (p = 0.145 for group effects, p = 0.071 for ROI effects, p = 0.605 for group x ROI interaction). (E) Representative micrographs showing the glial scar of Sarm1^+/+ and Sarm1^−/− mice with (F) corresponding quantification of the GFAP signal and correlation between GFAP and NeuN staining signal. Data in bar graphs are mean ± sem. n = 9 per group. Scale bars correspond to 100 μm in (A and C) and 500 μm in (E)