Fig. 4

Transient activation of the NG2 gene upon SWI in a subset of microglia. a Schematic of transgene structures of NG2^tdTxCXCR^EGFP mice used in SWI model. b Experimental plan: Subsequently after SWI, injured NG2^tdTxCXCR^EGFP mice were injected with tamoxifen (TAM) for three consecutive days from 0 to 2 days post injury (0–2 dpi), 2–4 dpi, or 4–6 dpi, and were analyzed at 7, 9, and 11 dpi respectively. c Overview of a coronal brain section of a NG2^tdTxCXCR^EGFP mouse at 7 dpi treated with TAM at 0–2 dpi. Along the injury site in the cerebral cortex, activation of EGFP⁺ microglia were detected in terms of increased cell density and EGFP expression. d Injured area (white box in c) shown in higher magnification. e Magnified view from white box in d showing a few tdT⁺ EGFP⁺ cells (arrowheads) at the lesion site. f Numbers of tdT⁺ EGFP⁺ cells found per coronal brain slice when tamoxifen was injected at different time points after SWI. The color coding shows the data points per animal (n = 3–5 mice indicated as big circles with 5–15 data points (small ones) per mouse). Scale bars = 1000 μm in c, 100 μm in d, and 50 μm in e