An extensive network of PHFτ‐rich dystrophic neurites permeates neocortex and nearly all neuritic and diffuse amyloid plaques in Alzheimer disease

Abstract
Previous studies demonstrated paired helical filament τ (PHFτ) in neuritic but not diffuse β‐amyloid (Aβ) plaques in Alzheimer's disease (AD). Re‐examination of amyloid deposits with antibodies to Aβ and PHFτ by conventional and confocal microscopy using double label immunohistochemistry showed that PHFτ is a component of both diffuse and neuritic plaques in AD. Unlike controls, a dense network of PHFτ positive dystrophic neurites extended throughout the AD neocortex permeating nearly all neuritic and diffuse plaques. Thus, PHFτ‐rich dystrophic neurites are common components of neuritic and diffuse plaques in AD neocortex.