Microanalysis of Alzheimer disease NFT and plaques.

Electron probe energy dispersive microanalysis of isolated andin situ neurofibrillary tangles (NFT) and neuritic (senile) plaque cores have been done to investigate the levels of Al, Si, Ca and Fe in the leading lesions of Alzheimer disease neuropathology. Varying levels of Si and Al, and to a lesser extent Ca, have been co-localized in about one half of the NFT and plaques examined using X-ray mapping. The variability of detection and the low levels of Al present indicates that aluminum is not required for the formation of the NFT and that aluminosilicates are not involved in the formation of the plaque core.