Figure 3.

Immunolocalization of PS1 in plaques and AVs within dystrophic neurites in AD and PS1/APP mice. Cingulate cortex from 9-mo-old PS1/APP mice immunolabeled with PS1 antibody and NT1 showed that PS1 localized to plaques (A). At higher magnification, anti-PS1 antibodies strongly labeled neuritic profiles that were distributed within the plaque corona (B). PS1 immunoreactivity is identified by IEM in AVs within dystrophic neurites of PS1/APP animals (C and D) and human brain (E and F) by IEM. Arrowheads identify tubulovesicular membrane labeling. PS1 (C–F, arrows) was localized on the outer limiting membrane of the AV but not in mitochondria (Mito) or on plasma membranes (PM). IEM followed by silver stain enhancement for PS1 was performed on a human brain that was diagnosed for AD (F).