Age-related progression of pathologic tau conformation and phosphorylation in neuronal cells of rT1, rT2, and rT3 mice. A, Representative photomicrographs of phosphorylated tau (red punctates) immunoreactive to the antibodies AT8, CP13, or PHF-1, and conformationally altered tau (red punctates) immunoreactive to the antibody MC1 in neuronal cells (NeuN staining in green) of the hippocampus (including CA1, CA2-3, and DG), primary Sm Ctx, and Ent Ctx of 18-month-old rT2 and rT3 mice. Scale bars, 100 µm. B-E, Scatterplots illustrating levels of tau reactive to antibodies AT8 (B), MC1 (C), CP13 (D), and PHF-1 (E) in the five anatomic brain regions (i.e., CA1, CA2-3, DG, Sm Ctx, and Ent Ctx) of rT1, rT2, and rT3 mice at varied ages. Semi-quan., Semiquantitative. M, months of age. For detailed gender distribution and numbers of animals used, see Table 1.