Fig. 4

Microglial changes in the peripheral retinal nerve fiber layer of Bax ^−/− mice after crush. a The number of AIF1-positive cells were quantified from retinal whole mounts of wild-type and Bax ^−/− mice after crush. Consistent with past literature, the number of microglia in the wild-type retinas rose dramatically by 7 days after crush, and remained significantly elevated at 14 days before declining at 21 days. Microglial counts in the Bax ^−/− mice were significantly attenuated relative to the wild types, and although a modest increase was quantified in both the experimental and control eyes (suggesting a contralateral effect from crush injury), the number of microglia in the crushed retinas of Bax ^−/− mice was significantly attenuated at 7 and 14 days post-crush. By 21 days, the microglial counts were no longer statistically significant between the two genotypes. Data is presented as mean ± SE. *P < 0.0001. For each genotype at each time point, n ≥ 3. b Sholl analysis of microglial morphology showing the numbers of processes crossing the 40-μm grid line (complete data shown in Additional file 1: Figure S1) for AIF1-positive cells in both crushed and contralateral control retinas of each genotype. Wild-type microglia exhibited an increase in processes at 7 days after crush (*P < 0.0001 relative to contralateral wild-type retinas), while microglia in Bax-deficient mice exhibited a significant decrease in processes by 14 days (**P < 0.0001, relative to control retinas). By 21 days, both control and crush retinas of each genotype exhibited similar levels of ramification, which were significantly reduced compared to earlier time points (P < 0.005). Data is presented as mean ± SE. A minimum of 50 cells from at least three mice, at each time point, were measured