Possible spatial and temporal correlation between astrocytes and round Iba-1+cells in the injured brain. Brain sections (30 μm) were obtained at the indicated times after LPS injection. (A, C) Immediately adjacent serial sections were stained with GFAP, Iba-1, and Vimentin antibodies, respectively. Lower panels are higher magnification of boxed areas in upper panels. (B, D) Sections were double-labeled with GFAP/Iba-1 (B) or GFAP/Vimentin (D). Arrows indicate astrocyte processes protruded towards monocytes (B, C). Arrows and arrowheads indicate Vimentin+ astrocytes near monocytes and Vimentin- astrocytes far from monocytes, respectively (D). Dotted lines in (A, B, and D) indicate the borders where GFAP+ astrocytes were absent and/or Iba-1+ round monocytes were present. Data shown are representative of at least three independent experiments. In each experiment, three or more animals were used for each time point. Scale bars, 1 mm (A), 200 μm (upper panels in C), 100 μm (B, lower panels in C, and D), 50 μm (lower panels in A).