Timecourse of spinal microglia activation in MIA-treated rats. (A) Positively identified spinal microglia were increased in the ipsilateral spinal cord of MIA-treated rats at days 7, 14 and 28, when compared to the contralateral spinal cord. Typical dorsal sections taken from spinal cords of MIA treated rats at days 7, 14 and 28 post- injection. (B) Quantification of positively identified activated microglia at the different timepoints in both treatment groups reveals significant differences. Data are expressed as mean % of the number of activated microglial in contralateral dorsal horn (100% baseline). Statistical comparison between number of Iba-1 positive cells in ipsilateral versus contralateral spinal cord were performed using a one-way ANOVA with a Dunnett's multiple comparison test *p < 0.05, **p < 0.01, ***p < 0.001. For comparisons between treatment groups, MIA versus saline-treated rats, a Kruskall Wallis test with a Dunn's post hoc test was used. **p < 0.01, ***p < 0.001.