Cuprizone treatment triggered microgliosis and inflammation in the corpus callosum of mice in a CX3CR1-independent manner. (A) Iba1 was immunostained on brain sections from WT and CX3CR1^−/− mice after 4 wk of normal show or a cuprizone-supplemented diet, the peak time point for microglial accumulation in the corpus callosum. Representative Iba1 immunostaining photomicrographs in the corpus callosum. The area covered by Iba1⁺ staining was measured in the corpus callosum using a stereological procedure (right). (B and C) TLR2 and C1qα mRNA was hybridized on brain sections from WT and CX3CR1^−/− mice after 4 wk of treatment with cuprizone or normal show. Semiquantitative expression levels of TLR2 (B) and C1q-α (C) mRNA signal were measured in the corpus callosum using ImageJ. The coronal sections at the bottom depict representative images of TLR2 (B) and C1q-α (C) in situ hybridization signal. One representative experiment out of two is shown. n = 3–6 mice/group. **, P = 0.01; ****, P < 0.001. Bars: (A) 100 µm.