6E10 immunohistochemistry reveals differential cell-associated hAPP/Aβ accumulation patterns and markedly late-stage extracellular plaque deposition in 3xTg-AD mouse hippocampus. Coronal mouse brain sections (30 μm) were prepared from 3xTg-AD mice sacrificed at 2 (A, I, Q), 3 (B, J, R), 6 (C, K, S), 9 (D, L, T), 12 (E, M, U), 15 (F, N, V), 18 (G, O, W), and 26 months of age (H, P, X) and were processed for immunohistochemistry using the 6E10 monoclonal antibody to detect both human amyloid precursor protein (hAPP) and Aβ peptides. CA1 hippocampal sections at Bregma -1.8 mm (A–H), at Bregma -2.5 mm (I–P), and at Bregma -2.8 mm (Q-X), were examined for regional and temporal patterns of hAPPswe transgene/Aβ peptide expression and photomicrographs were obtained at 10×. The inset in panel X represents a 40× digitally magnified image of the photomicrograph for better visualization of stained cell morphology. Scale bar in D represents 200 μm.