Immunization initiated at 3 months of age in Tg2576 animals decreases total amyloid deposits. A. Representative photomicrographs of sections from brains (hippocampus and cortex) of 14 months Tg2576 (Control, Aβ oligomer, IAPP oligomer, 3A peptide and Aβ fibril) that have been vaccinated as described in materials & methods from 3 to 14 months of age immunostained with 6E10 (which reacts with the human amyloid peptide). Scale bar: 100 microns B. Quantitation of plaque load. Image analysis (% Field area) of Aβ (6E10 antibody) immunoreactivity in hippocampus and cortex of immunized animals at 3–14 months is expressed as % of untreated control mice. The mean value for each animal was determined as the average of 2 sections (except untreated control which is 1 section per animal) using 4–8 images per section (most to all of the area of the section was analyzed). Bars represent group mean ± SEM of n mice per group: Control n = 8, Aβ oligomer n = 8, IAPP oligomer n = 8, 3A oligomer mimic n = 8 and Aβ fibril n = 6, *p < 0.05 and **p < 0.01 by ANOVA (B).