Fig. 5. Reductions in AF-related phenotype persist for months after microglial repopulation in aged mice.

(A) Timeline of experimental design for the chronic 12-week microglial repopulation period is shown. (B) Representative dot plots of young and old microglia at 12 weeks after repopulation. Quantification of microglia counts per hemisphere is shown. Representative histograms and quantification of the AF-related phenotype as measured by MFI of (C) FITC AF, (D and E) lipid content, (F) iron accumulation, (G and H) proinflammatory cytokine production, and (I) ROS production. PLX5622 treatment (i.e., elimination and repopulation) showed enduring decreases in all AF-related microglial biomarkers. N = 4 to 6 per group. FMO controls are shown in gray, young groups are shown with no outline, old groups are shown with bold outlines, and treatment groups are color-coded according to bar graph and figure legend (Veh in red and PLX5622 in blue). A vertical fiducial line is included for reference. ns, not significant. Data were analyzed using two-way ANOVA with Tukey post hoc correction for multiple comparisons (*P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001).