Figure 1.

Chronic microglial phagocytosis impairment reduces adult hippocampal neurogenesis. A, Representative maximum projection of confocal z-stack of P2Y12 and MerTK/Axl KO mice immunofluorescence in the mouse hippocampal DG at 1 month (1 m). Microglia were labeled with Iba1 (cyan) and apoptotic nuclei were detected by pyknosis/karyorrhexis (white, DAPI). B, C, Percentage of apoptotic cells engulfed (Ph index), weighted average of the percentage of microglia with phagocytic pouches (Ph capacity), apoptotic cells and microglia per septal hippocampus in P2Y12 KO mice (B) and MerTK/Axl KO mice (C). D, Representative confocal z-stack of P2Y12 and MerTK/Axl KO mice immunofluorescence in the mouse hippocampal DG at 1 m. Neuroblasts were labeled with DCX (green) and proliferation was labeled with either BrdU (150 mg/kg, 24 h) or Ki67 (magenta). E, Neuroblast and neuroblast proliferation in 1-month-old P2Y12 KO mice. F, Neuroblast and neuroblast proliferation in 1-month-old MerTK/Axl KO mice. Scale bars: A, D, 50 μm (inserts, 10 μm); A, left, z = 20 μm; A, right, z = 17 μm; D, left, z = 7 μm; D, right, z = 10 μm. N = 3–4 mice (B, C, E, F). Error bars represent mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001 by Student's t test. Only significant effects are shown. Values of statistics used are shown in Table 2.