Figure 5.

TgF344-AD rats have tau hyperphosphorylation and neurofibrillary tangles. A, Photomicrographs are shown of cingulate cortex from 16-month-old WT or TgF344-AD rats reacted with Gallyas silver stain (top) or phospho-tau antibody CP13 (bottom). Insets show representative dysmorphic neurons, and scale bars denote 25 μm. B, Comparison of tau pathology among AD patients, TgF344-AD rats, Tg2576, and PSAPP mice. Photomicrographs are shown from cingulate cortex stained with MC1 antibody, and scale bar denotes 10 μm. C–E, Three-step extracted brain homogenates from WT or TgF344-AD rats were assayed for phospho-tau by WB. Western blots are shown using pTau-PADRE primary antibody (C) on brain homogenates from Tg versus WT rats from 6 to 26 months of age in the crude pellet fraction. Densitometry results are shown for crude pellet (D) or Sarkosyl insoluble (E; top) or pTau-PADRE-reactive tau ratios for each fraction (bottom) (normalized to total input tau). Bars represent the mean ratios ±SEM for each WT or Tg cohort (aged 6–26 months, n = 5; 16 months, n = 7; 26 months, n = 8). F, The pTau-PADRE antibody was incubated with or without excess blocking peptide and reacted with AD patient cortex.