Fig. 5

Young and old BM-derived microglia are differentially polarized in the aged brain. a Immunostaining and quantification for anti- and pro-inflammatory markers Arg-1 and iNOS, respectively. n = 5 mice per group. b RTqPCR on whole brain and ELISA on different brain regions for common soluble factors produced by Arg-1⁺ microglia. c Immunostaining and quantification of GFP⁺ microglia positive for insulin-like growth factor 1 (IGF-1) and fibroblast growth factor 2 (FGF2) in Y⁺-O brains for n = 5 mice per group. Scale bar, 40 μm (a, b). Data are mean ± s.e.m. **P ≤ 0.01; ***P ≤ 0.001; ****P ≤ 0.0001 (two-way ANOVA with Tukey’s multiple comparisons test (a (F (1, 16) = 10.33, P = 0.0054), b (top left; F (1, 32) = 193.9, P < 0.0001, top right; F (1, 16) = 4.068e^−0.005, P = 0.9950, bottom left; F (1, 16) = 118.1, P < 0.0001, bottom right; F (1, 16) = 703.6, P < 0.0001)) and unpaired two-sided t-test (c))