Paired helical filaments of the Alzheimer type in cultured neurones

Abstract

ALZHEIMER'S disease, a common progressive dementia of later life, is associated with several histopathological changes. Although one of these pathological changes, neuritic plaques with amyloid cores, has been reproduced in brain of mice following inoculation with scrapie agent^1,2, Alzheimer-type neurofibrillary degeneration has not yet been reproduced in the laboratory. This unique form of human neurofibrillary degeneration is composed of arrays of paired 100-Å diameter filaments twisted into a helical configuration with a period of approximately 800 Å (refs 3, 4). We present here evidence that paired helical filaments morphologically closely resembling those found in the human disease are induced in cultured human foetal cerebral cortical neurones after exposure to an extract prepared from Alzheimer-affected brain.