Fig. 8.

Both noise and DTX treatment induce microglial activation and DTX also causes peripheral immune infiltration into the brain. a Microglia are moderate expressors of both CD11b and CD45, whereas peripheral immune cells express high levels of CD45. Using flow cytometry with this gating strategy, we were able to evaluate the activation of microglia and identify CD11b⁺ and CD11b⁻ infiltrates from the periphery in the brains of LysMCre^+/+iDTR^+/+ mice. b CD68, CD86, and MHC-II are markers of microglial activation, demonstrating that both noise and DTX activate central immune responses. c CD45^hi CD11b⁻ (e.g., lymphoid) cells showed increased infiltration into the brain upon DTX treatment. d Myeloid infiltrates were detected by their expression of CD11b and their high expression of CD45. Despite ablation of these cells in the periphery, there was considerable migration of myeloid cells into the brain following DTX treatment, which also comprised monocyte- (e) and macrophage- (f) containing subpopulations. Original flow cytometry plots are shown for all cell types. Data points are measurements from individual animals; one-way ANOVA with Tukey’s multiple comparison test or respective non-parametric test (b–f). ^*P < 0.05 vs. control; ^#P < 0.05 vs. noise