title: Ultrastructure of paired helical filaments of Alzheimer's neurofibrillary tangle.
abstract: Isolated paired helical filaments (PHF) of Alzheimer's disease and senile dementia of the Alzheimer type (AD/SDAT) were studied by negative stain techniques and electron microscopy (EM). The helical structure of the PHF was confirmed by tilt analysis of negatively stained isolated PHF. A substructure of four protofilaments, each 3-5 nm in diameter, was also observed. A comparison of PHF substructure, neurofilaments and microtubules, revealed no similarity among the three structures.
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000473:pathology*; D002540:Cerebral Cortex / Q000648:ultrastructure; D003599:Cytoskeleton / Q000648:ultrastructure; D006801:Humans; D008854:Microscopy, Electron; D008875:Middle Aged; D009454:Neurofibrils / Q000648:ultrastructure*