Microglia were positive for NOX2 ipsilateral to the injury site. Microglia were labeled with CD11b (green) and immunostained with an antibody against NOX2 (red) in sham-injured tissue and at 24 hours, 7 days, and 28 days post-injury. Co-labeled cells are indicated with arrows. NOX2+ cells increased by 24 hours post-injury and increased further by 7 days post-injury, but by 28 days post-injury staining resembled sham. Bar = 20 μm (A, B, D); 50 μm (C).