Neurofibrillary tangles have no obligatory predilection for acetylcholinesterase-rich neurons

Parts of the brain that are prone to NFT formation normally contain many neurons that are intensely acetylcholinesterase (AChE)-positive. In this study, we used thioflavin-S immunofluorescence, AChE histochemistry, and AChE immunocytochemistry to investigate the possibility that intense AChE positivity may act as a perikaryal marker for the vulnerability to NFT formation. Our observations in entorhinal and motor cortices and in the subthalamic nucleus demonstrate major mismatches between the distribution of AChE-rich neurons in normal brains and the distribution of NFT in AD. There is therefore no obligatory relationship between intense AChE positivity in the premorbid period and subsequent vulnerability to tangle formation.