Percent increase in relative nerve signal intensity in the setting of minocycline and USPIO treatment. The signal intensity of the injured left and uninjured right sciatic nerve proximal to the site of injury was normalized to that of the adjacent muscle. Asterisks denote injured left nerve treatment groups that were significantly different from the untreated control animals (Bonferroni’s post hoc multiple comparison test, p < 0.05 for +USPIO versus +MINO +USPIO; p < 0.001 for +MINO +USPIO and for +USPIO versus -MINO -USPIO; no difference between +MINO and –MINO -USPIO). The signal intensity of uninjured right nerve was only mildly higher than that of surrounding muscle (3 to 13%), which was independent of minocycline and/or USPIO administration. Data represent the averages and standard deviations of three animals in each group.