Figure 4

Global HI induced activation and proliferation of microglia in the hippocampus, PVWM and SCWM. Microglial proliferation and activation was shown by significantly increased areal fraction (%) of IBA-1 immunoreactivity (IR) and by loss of processes and amoeboid morphology, respectively. (A) Global HI significantly increased areal fraction (%) of IBA-1 IR in the hippocampus; (B) Sham, hippocampus; resting microglia, also depicting the analyzed hippocampal sub-regions (see Figure  5); I = cornu ammonis (CA)1-2, II = CA3, III = dentate gyrus (DG); (C) HI, hippocampus; profound microglial proliferation and activation (scale bar = 500 μm); (D) Global HI significantly increased areal fraction (%) of IBA-1 IR in the PVWM; (E) Sham, PVWM; resting microglia (scale bar = 200 μm, scale bar insert = 25 μm); (F) HI, PVWM; proliferation and activation of microglia (scale bar = 200 μm, scale bar insert = 25 μm); (G) Global HI significantly increased areal fraction (%) of IBA-1 IR in the SCWM; (H) Sham, SCWM; resting microglia (scale bar = 200 μm, scale bar insert = 25 μm); (I) HI, SCWM proliferation and activation of microglia (scale bar = 200 μm, scale bar insert = 25 μm). (A, D, G) Geometric means ± 95% CI are depicted. *P ≤0.05, # P ≤0.01, ‡ P ≤0.001, NS, non-significant. HI = hypoxia-ischemia.