Fig. 6
β1 integrin blockade strongly stimulated microglial proliferation in the hypoxic young but not aged brain. Frozen brain sections taken from young (8–10 weeks) and aged (20 months) mice exposed to normoxia or hypoxia (8% O2) that received daily intraperitoneal injections of the anti-mouse β1 integrin function-blocking antibody or isotype control antibody for 4 days were stained for Mac-1 (AlexaFluor-488) and Ki67 (Cy-3) (A). Images were captured in the midbrain. Scale bar = 100 μm. Quantification of the number of Mac-1+/Ki67+ cells/FOV in young (B) or aged (C) brain after 0- or 4-days hypoxia. Results are expressed as the mean ± SEM (n = 6 mice/group). ***p < 0.01. Note that β1 integrin blockade strongly increased microglial proliferation in the young hypoxic brain, but not in the aged brain