Fig. 4

Flow cytometry analysis of different microglia/macrophages populations in the retina after systemic LPS challenge. Microglia/macrophages were gated as GFP⁺CD11b⁺ cells (a, left panel) and were further gated as CD45^low microglia and CD45^hi macrophages (a, right panel). MHC-II expression in microglia and macrophages was increased in the LPS-challenged group (b). The numbers of GFP⁺CD11b⁺ microglia/macrophages (c, ***p < 0.001, unpaired t test), GFP⁺CD11b⁺CD45^low microglia (d, **p < 0.01, unpaired t test) and GFP⁺CD11b⁺CD45^hi macrophages (e, ***p < 0.001, unpaired t test) were elevated in the LPS group. Microglia (f, **p < 0.01, unpaired t test) and macrophages (g, **p < 0.01, unpaired t test) activation was also increased in the LPS group. The pie chart depicts the composition of the GFP⁺ cells in the retina after four consecutive LPS challenges (h)