5XFAD mice exhibit Caspase-3 activation in Layer 5 cortex and subiculum. Parasagittal brain sections from representative 4 and 9 month old 5XFAD (A-D, I-L), non-transgenic littermate (Non-Tg; E, F, M, N), and 5XFAD; BACE1−/− (G, H, O, P) mice were incubated with an antibody against activated Caspase-3, visualized by DAB staining, and micrographed in Layer 5 cortex (A-H) and subiculum (I-P). The levels of activated Caspase-3 immunolabeling are significantly higher in the brains of both ages of 5XFAD mice compared to those of 5XFAD; BACE1−/− or non-transgenic mice. In addition, punctate aggregates of activated Caspase-3 are distributed throughout 5XFAD sections (black arrows, A-D, I-L), but are absent in 5XFAD; BACE1−/− or Non-Tg sections (E-H, M-P). Boxes in A, B, I, and J are enlarged in C, D, K, and L, respectively. Scale bar A, B, E-H, I, J, M-P = 80 μm; C, D, K, L = 40 μm.