T cells primarily infiltrate the LM and brain, but not the dura, during EAE independent of age. Clinical scores were tracked in mice in which EAE was induced by adoptive transfer of 10 million Th17-skewed encephalitogenic T cells into young and aged SJL/J mice. (A) Mice developed clinical disability, including paralysis (reflected in increased clinical score). At various time points throughout the disease, mice were euthanized, and the dura, LM, and brain were collected and analyzed by flow cytometry. (B and C) Mice were analyzed at naïve (day 0, n = 7–8), early onset (day 7, n = 4–6), late onset (day 9, n = 4–6), acute phase (day 11, n = 6–14), and post-acute phase (day 25, n = 11–13) time points. Results are data from two repeat experiments. Results are expressed as the absolute number of cells in the whole tissue (B) or as a fold change from naïve mice (C). Error bars indicate mean ± SEM. A two-way ANOVA (A and B)/mixed-effects analysis (C) followed by Bonferroni (A), Sidak’s (B), or Dunnett’s (C) multiple comparison test was conducted to assess statistical significance (* = P < 0.05, ** = P < 0.005, *** = P < 0.0005, **** = P < 0.0005, and no label = not significant). The two variables compared in the mixed-effects model, or two-way ANOVA, were days postadoptive transfer (time) and either age (A and B: young versus aged mice) or tissue type (C: dura versus LM and brain). Of note, statistical significance in graphs plotting immune cell populations as a fold change from naïve in C was evaluated using Dunnett’s by comparing the brain and LM with the dura within each time point.