(A) Mice were subjected to immunofluorescence for GFP (green), HT7 (cyan), and Hoechst (blue) in the EC, DG, CA3 and CA1. EC scale bar, 50 μm; DG, CA3 and CA1 scale bar, 20 μm. (B) Quantification of hTau positive signal (HT7) in EC, DG, CA3 and CA1. Data were presented as mean ± SD (n = 3 each group, two-way ANOVA followed by Tukey post hoc test). *, P < 0.1. (C) TLR4 KO decreased interstitial fluid hTau level in DG subset collected by microdialysis, but the reduction was not statistically significant measured by ELISA. Data were presented as mean ± SEM (n = 6, each group, Student’s unpaired t-test).