(A) LPS increased hTau spreading from EC to hippocampal subsets (DG, CA3 and CA1), and GC attenuated hTau transmission (Tau13) without suppression of microglia activation detected by immunohistochemical staining. Tau13 specifically reacts with human tau; scale bar, 10 μm. Average optical density (AOD) was used to estimate the intensity of Tau13 (B), IBA1 and CD68 (C). Data were present as mean ± SD (n = 3 each group, two-way ANOVA followed by Tukey post hoc test). *, P < 0.05; **, P < 0.01; ***, P < 0.001 versus P301L-LPS. (D,E) LPS-induced hTau transmission was co-localized with the activated microglia in hippocampal DG subset measured by co-immunofluorescence, and GC treatment attenuated hTau transmission without suppression of microglia activation. Data were present as mean ± SD (n = 3 each group, one-way ANOVA followed by Tukey post hoc test). ***, P < 0.001. (F) LPS increased hTau level in DG interstitial fluid measured by microdialysis and ELISA, and GC attenuated the elevation of hTau in DG subset; scale bar, 50 μm. Data were present as mean ± SEM (n = 6∼8 each group, one-way ANOVA followed by Bonferroni post hoc test). *, P < 0.05; **, P < 0.01.