Fig. 3

Cortical pSyk burden is age-dependently increased in Aβ-overexpressing mice, particularly in microscopic fields containing Aβ deposits, compared to wild-type littermates. Cortical pSyk burden (area covered) of immunofluorescence images (Fig. 1) was quantified in 45 ± 0.3-week-old (avg. ± SEM) (a) and 116 ± 13.5-week-old (avg. ± SEM) (b) Tg APPsw (n = 6) and Tg PS1/APPsw mice (n = 6), compared and normalized to wild-type littermates (n = 6). Microscopic fields containing Aβ deposits were distinguished from microscopic fields not containing Aβ deposits as described in the materials and methods section. Kruskal-Wallis and post-hoc Dunn’s multiple comparison test revealed a significant increase (p < 0.001) in pSyk in fields containing Aβ deposits in younger Tg PS1/APPsw animals compared to age-matched wild-type littermates (a). pSyk burden in older Tg APPsw and Tg PS1/APPsw mice was statistically significantly increased in cortical microscopic fields containing Aβ deposits compared to age-matched wild-type littermates (p < 0.001). Older Tg PS1/APPsw mice also exhibited a statistically significant pSyk burden increase in microscopic fields not containing Aβ deposits (p < 0.001), whereas the pSyk burden in Tg APPsw in microscopic fields not containing Aβ deposits was not statistically different from wild-type littermates (P > 0.05). Six animals per genotype were analyzed. Error bars represent SEM