Propofol attenuates microglia activation after traumatic brain injury (TBI). (A–C) Western blot analysis showed a significant increase in microglia markers ED1 and Iba-1 at 7 days after fluid percussion injury. Propofol-treated (n = 4) TBI tissue had significantly reduced ED1 and Iba-1 expression when compared with isoflurane-treated (n = 4) TBI tissue. (D) Representative Iba-1 immunohistochemical images displaying ramified, hypertrophic, and bushy microglial phenotypes based on cellular morphological features. (E) Unbiased stereological quantification of microglial cell number and activation phenotype in each group 28 days postinjury. Propofol-treated TBI tissue had significantly reduced numbers of bushy microglia when compared with isoflurane-treated TBI tissue, N = 4 rats per group. *P < 0.05, **P < 0.01, ***P < 0.001 versus sham; #P < 0.05, ##P < 0.01, ###P < 0.001 versus isoflurane. Statistical analyses were performed by one-way ANOVA followed by Student–Newman–Keuls post hoc test. GAPDH = glyceraldehyde-3-phosphate dehydrogenase; Iba-1 = ionized calcium-binding adapter molecule 1.