Fig. 8

The expression of different microglia phenotypes in M1 and PMC. a Pie charts of %microglia by morphology and C1q expression in M1 and b PMC. Right inset in a shows a Box-and-whisker plot of the ratio of Hyper + to the total Hyper microglia (two-way ANOVA group*area: interaction, p < 0.01; Fisher’s LSD post hoc, p < 0.05, see Table S3). c Line plots showing the mean relative proportion of Rami + , Hyper + , Hyper-, and Total C1q + as a percentage of total microglia in M1 and PMC (two-way ANOVA: main effect ‘group’ %Hyper + ; ‘group*area’ interactions %Rami + , %Hyper-, and %Total C1q + , p < 0.05). Between-area comparisons: in control, %Rami + and %C1q is greater in M1 than PMC; and in vehicle, %Rami + is greater in PMC than in M1, but %Hyper- is greater in M1 than in PMC (Fisher’s LSD, p < 0.05; Ctr: n = 3; Veh: n = 4; EV; n = 5 monkeys). d Representative reconstructions of microglia morphological subtypes. e–g Morphological parameters measured from partial 3D reconstructions (Ctr: n = 36 cells; Veh: n = 58 cells; EV: n = 71 cells each from 1 monkey): e number of primary process (three-way ANOVA group*morphology*C1q ± , main effect ‘morphology’: p = 0.02; ‘group’: p = 0.01; Table S3). Between-group comparisons: Hyper ± microglia in EV had more primary processes than in veh/ctr. Between-morphology comparisons: In EV, Hyper ± microglia had more primary processes than Rami ± microglia (Fisher’s LSD, p < 0.05). f Microglia soma surface area (three-way ANOVA, main effect ‘group’: p = 0.006; ‘C1q ± ’: p = 0.004). Between-group comparisons: Hyper + and Rami + microglia in EV had greater soma surface area than in ctr (p < 0.05). g Soma aspect ratio was greater in C1q- microglia than in C1q + (main effect ‘C1q ± ’: p = 0.03). Left panel shows plots by microglia morphology and C1q subtype. Middle panel shows plot by total C1q+ vs C1q- microglia. Right panel shows example image with aspect ratio measurement. h 3D scatter plot of morphological parameters. Annotations based on morphology, C1q expression, and experimental group. Box-and-whisker plots: bars show interquartile range and median (horizontal line) with error bars = 95% confidence interval; *p < 0.05, **p < 0.01. Table S3 for exact p-values