Immunization of Tg2576 mice at 16 – 20 months provided no significant change in brain pathology. Image analysis of immunoreactivity in sections of cortex/hippocampus of animals immunized at 16–20 months. Animals were immunized and tissue processed and stained for thioflavine (A), 6E10 (B), CD45 (C) and GFAP (D) as described above for the younger animals. Mean of each animal is the average of 2–3 assays/sections per marker, derived from 4 – 8 images per section (including most to all of the area of study). Bars represent group mean ± SD of n mice per group: Control (untreated) = 4–6, CFA n = 6, oligo Aβ n = 6–7, fAβ n = 4–6. No significant differences are seen between groups in any of the markers.