Tau expression in the cortex (A, C, E) and hippocampus (B, D, F) of 4-10-month-old mice was determined by western blot analysis (C-F).(C, D) Western blots from Figure 1A and B were enhanced to better reveal tau fragments of ~40 kDa. (E, F) Quantitation of western blot signals for tau fragments of ~40 kDa detected with Tau5 in tissue homogenates. n = 3-4 mice per group. *P < 0.05, **P < 0.01, ***P < 0.001 by two-tailed unpaired t test (A, B) or by Welch's one-way ANOVA with post-hoc two-tailed Welch's t test (E, F). P values were Holm-adjusted. Values are means ± SEM. 