Figure 2.

Progressive accumulation of insoluble Tau species in P301S mice. a, Representative Western blots of hippocampal extracts from WT and P301S mice at different ages probed with AT8 antibody, stripped, and re-probed with HT7 to detect total hTau. Note the absence of a detectable AT8 or HT7 signal in WT extracts (first two lanes). b-d, The amount of AT8⁺ Sarkosyl-soluble Tau normalized to total hTau in the supernatant and the amount of insoluble AT8⁺ Tau normalized to total hTau in the pellet is statistically indistinguishable between the investigated time points (not significant). The ratio of insoluble/soluble Tau increased with age (12–14 weeks vs 20–22 weeks, ***p = 0.0008; 16–18 weeks vs 20–22 weeks, **p = 0.0011). e, Representative Western blots of hippocampal extracts from WT and P301S mice at different ages probed with AT180, stripped, and re-probed with HT7 to detect total hTau. Note the absence of a detectable AT180 signal in WT extracts. f-h, The amount of AT180-immunoreactive Sarkosyl-soluble Tau normalized to total hTau (HT7) in the supernatant did not change over time (not significant), while the amount of insoluble AT180⁺ Tau normalized to total hTau in the pellet increased with age (12–14 weeks vs 20–22 weeks, *p = 0.0401). The ratio of insoluble/soluble Tau increased significantly with age (12–14 weeks vs 20-22 weeks, **p = 0.0026; 16–18 weeks vs 20–22 weeks, **p = 0.0073). Data are mean ± SEM. n = number of hippocampi as indicated in the bar graphs from N = 3 or 4 animals. Data were analyzed using one-way ANOVA with Tukey post hoc test: *p < 0.05; **p < 0.01; ***p < 0.001.