Striation is the characteristic neuritic abnormality in Alzheimer disease

• Published in: Brain research 1998-12, Vol.813 (2), p.329-333
• Main Authors: Velasco, Manuel E., Smith, Mark A., Siedlak, Sandra L., Nunomura, Akihiko, Perry, George
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Alzheimer disease; Alzheimer Disease - metabolism; Alzheimer Disease - pathology; Argyrophilic grains; Axonal transport; Axonal Transport - physiology; Biological and medical sciences; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Humans; Image analysis; Medical sciences; Microscopy, Electron; Microtubules - metabolism; Middle Aged; Neurites - metabolism; Neurites - pathology; Neurites - ultrastructure; Neurofibrillary tangles; Neurofibrillary Tangles - pathology; Neurofibrillary Tangles - ultrastructure; Neurology; Neurons - metabolism; Neurons - pathology; Neurons - ultrastructure; Neuropil - pathology; Neuropil threads; Synapses - metabolism; Synapses - pathology
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/S0006-8993(98)01034-8

In this study, we found that neuropil threads of Alzheimer disease, rather than being continuous filaments along cell processes, show multiple interruptions. They are segmental in nature and therefore appear as striations rather than continuous filaments along the length of the neurite. Neuritic striation is not an artifact of section thickness since the majority of abnormal filament accumulations are extremely short. The dominance of short striations demonstrates that argyrophilic grains, rather than being distinct structures, simply represent a short variant of striation and that longer striations are arbitrarily considered neuropil threads. Ultrastructural examination showed that the intervals between striations lack a cytoskeleton. We suggest that neuritic striations may interrupt the microtubule system functionally blocking fast neuritic transport as well as playing a role in loss of neuronal connectivity.