EXTENSIVE NETWORK OF PHF-TAU-RICH DYSTROPHIC NEURITES PERMEATES NEOCORTEX AND NEARLY ALL NEURITIC AND DIFFUSE AMYLOID PLAQUES IN ALZHEIMER-DISEASE

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