The fine structure of neurofibrillary tangles in Alzheimer's disease.
J Neuropathol Exp Neurol. 1963 Oct;22:629-41.
The neurofibrillary tangle of Alzheimer is one of the most distinctive cytopathologic changes that occurs in the central nervous system. This communication presents the ultrastructure of neurofibrillary tangles as they were seen in brain biopsies of two patients with advanced Alzheimer's disease. The relation between these abnormal formations and certain other cell structures will be discussed.
1. Electron microscopic studies of two cortical biopsies in Alzheimer's disease are reported.
2. Neurofibrillary tangles were made of bundles of 100A hollow fibrils occupying the neuronal cytoplasm and displacing the normal organelle.
3. In the affected neurons the mitochondria were swollen and watery.
4. The neuropil was normal save for moderate gliosis. The long glial processes contained solid 60A fibrils.
5. Neurofibrillary tangles and glial fibrils were never seen except inside cells.
6. The hypothetical neurofibril diagram of Schmitt and Davison is noted to be remarkably similar to the electron micrographs of filaments in both normal and diseased human neurons.