title: Neurofibrillary tangles of paired helical filaments.
abstract: The abnormal aggregates of fibrillar material found in neurons in Alzheimer's disease, senile dementia, the Guam Parkinsonism-Dementia complex, Down's syndrome, and postencephalitic Parkinsonism were studied by means of tilt-stage electron microscopy and with X-ray images of scale models of a bifilar helix. The model fulfills the structural criteria established by electron microscopy. These studies showed that the "twisted tubule" which makes up the neurofibrillary tangle in many pathological situations is a bifilar helix made up of 130 A filaments.
mesh_terms: D000544:Alzheimer Disease / Q000473:pathology; D001927:Brain Diseases / Q000473:pathology*; D003704:Dementia / Q000473:pathology; D004314:Down Syndrome / Q000473:pathology; D006801:Humans; D009454:Neurofibrils / Q000648:ultrastructure*; D010300:Parkinson Disease / Q000473:pathology; D010301:Parkinson Disease, Postencephalitic / Q000473:pathology