Total Aβ is reduced by 3D6 treatment. Representative images of Aβ staining in the hippocampus of APP/PS1, control, and IgG2a (A), APP/PS1, control, and 3D6 (B), APP/PS1, HHcy, and IgG2a (C), and APP/PS1, HHcy, and 3D6 (D). A, The cornu ammonis (CA) 1, CA3, and dentate gyrus (DG) are labeled for orientation. Scale bar: A, 120 μm. E, Quantification of percentage positive stain in the frontal cortex and hippocampus. *p < 0.05, compared with APP/PS1, control, and IgG2a. F, Biochemical quantification of soluble and insoluble Aβ1–38, Aβ1–40, and Aβ1–42 ± SEM.