Fig. 4
From: The neuropathological diagnosis of Alzheimer’s disease
Neurofibrillary Tangles. Neurofibrillary tangles develop from intracellular pre-tangles containing misfolded tau and small tau aggregates to mature NFTs containing bundles of cross-linked tau filaments before the neuron dies and an extracellular ghost tangle (asterisk) remains. Silver staining (a) and Thioflavin S (b) capture many mature tangles (arrows) and some pre-tangles (arrowheads) along with amyloid plaques and tau neuropil threads. Development of NFTS from the pre-tangles is more easily visualized using tau immunohistochemistry (c, d). This allows the mis-localized somal tau to be distinguished readily from the bundles of PHFs in NFTS in addition to the neuropil threads that can also be pronounced (d). The scale bars are 40 μm