FIGURE 3.

TBI-induced formation of rod microglia was associated with limited microglial proliferation. Adult C57BL/6 mice were uninjured (control) or were subjected to midline fluid percussion injury (TBI). Following TBI, mice were provided ad libitum access to drinking water containing 0.8 mg/ml 5-bromo-2-deoxyuridine (BrdU) for 7 days. Mice were also injected with BrdU (50 mg/kg) at 0900 and 1400 (light phase). At 7 days postinjury (dpi), brains were perfused, fixed, sectioned, and labeled for Iba1 and BrdU. (a) Representative images of BrdU labeling (20×) in the somatosensory cortex of control and TBI mice. Inset indicates region used for analysis. (b) Percent-area of BrdU labeling in the somatosensory cortex (n = 4). (c) Representative images (20×) of Iba1 labeling (top) and merged BrdU labeling (bottom). Arrows highlight the Iba⁺/BrdU⁺ rod microglia. (d) Number of Iba1⁺ rod microglia that were either BrdU⁺ or BrdU^neg (n = 3). Bars represent mean ± SEM. Means with (*) are significantly different from controls (p < .05) and means with (‡) tend to be different from controls (p = .1)