Small intestine immunoreactivity for cox-2 and MAP2 decreased in APP−/− mice compared to wild type controls with no change in occludin. Ileum tissue samples were collected from C57BL6/J wild type and APP−/− mice, fixed in 4% paraformaldehyde, serially sectioned, and immunostained. Tissue sections were immunostained using anti-APP, cox-2, occludin and MAP2 antibodies and antibody binding was visualized using Vector VIP as the chromagen. Arrows indicate the location of immunoreactivity shown as an enlarged inset to the right of each panel. Representative images from 5 animals per condition are shown.