IL-6 blockade has a limited effect on astrocyte activation. (A) GFAP mRNA expression analyzed by real-time PCR at day 32 post immunization in the spinal cords of WT, GFAPγR1Δ + α-β-gal, and GFAPγR1Δ + α-IL-6 mice with n = 3 to 4 individual mice per group. Statistics were calculated with one-way ANOVA with Bonferroni post-test with ***P < 0.001. (B) Immunohistochemical staining for GFAP in WT, GFAPγR1Δ + α-β-gal, and GFAPγR1Δ + α-IL-6 mice. Upper panels show GFAP labeling within areas of white matter demyelination. Lower panels show GFAP labeling in gray matter distal from areas of demyelination. Bar = 50 μm.