Thioflavine positive plaques are decreased in TG 2576 mice immunized from 12–16 months with oligomeric or fibrillar Aβ conformations. A. Cortex of Tg2576 at 16 months was stained with thioflavine as described in Materials and Methods (control: untreated, CFA: adjuvant only, Oligo Aβ: colloidal gold conjugated amyloid β, and fAβ1–42: fibrillar amyloid). Scale bar = 100 microns. B. Image analysis of thioflavine in hippocampus and cortex of animals immunized at 12–16 months. Mean of each animal is the average of 2–4 sections (except untreated control which is 1 section per animal) in which most to all of the area of study was analyzed (total 4–8 images per section). Bars represent group mean ± SD of n mice per group: Control n = 9, CFA n = 4, oligo Aβ n = 7, Aβ n = 5. *p < 0.02, **p < 0.005 by ANOVA relative to CFA (adjuvant only) control.