Anti murine activated C3 is detected in plaque-like structures in Tg2576 and is decreased in animals immunized with either fAβ or oligo Aβ. A. Photomicrographs of immunohistochemical straining with 2/16 anti mouse C3b/iC3b (brown) in Tg2576 untreated or immunized with CFA, Oligo Aβ and fAβ at 12–16 mo. Scale bar = 20 microns. B. Anti C3b/iC3b immunoreactivity in animals immunized at 12–16 months. Values for each animal were the average of 6–8 images per section which resulted in analysis of most to all of the area of the section. Bars represent group mean ± SD of n mice per group: Control n = 4, CFA n = 3, oligo Aβ n = 6, fAβ n = 5. *p < 0.002, **p < 0.001 relative to CFA, by ANOVA.