Assessing BBB dysfunction. A. Summary table indicating successful scans (✓) performed at each stage after infection. B. The degree of BBB dysfunction was determined by calculating the percentage signal change present in the brain following CE-MRI. Significant levels of barrier impairment were detected on day 14 post-infection compared with uninfected animals or those scanned at 7 days post-infection. A stepwise increase in BBB dysfunction was detected at days 21 and 28 post-infection. Dots represent the group mean (n = 2–4 in each group), bars represent one standard error of the mean. The means of groups that do not share a letter are significantly different (p < 0.05) from each other.