Immunohistochemistry of macrophagic and microglial markers in brain tissue after traumatic brain injury over time. Maximum immunofluorescence detection of markers of macrophagic and microglial polarization occurred by 5 days postinjury (DPI). (A) Representative anatomical localization of the regions of interest (ROIs; rectangles) quantified for the immunofluorescence of each marker. These ROIs were examined for the same anatomical slices from each animal. Scale bar = 3 mm. (B) Quantification of immunofluorescence in ROIs and representative immunofluorescent images at 1 DPI and 5 DPI. For a given time point, the column represents the average of all three ROIs for each slice, as shown in (A). Iba1, Ionized calcium-binding adapter molecule 1. Error bars indicate standard errors of the mean. *P < 0.05 for time point relative to 1 DPI. Scale bars = 100 μm.