Detection of aluminum by SEM - X-ray spectrometry within neurofibrillary tangle-bearing neurons of Alzheimer's disease

Neurons from the hippocampus in autopsy-derived brain tissue from three patients with senile dementia and three nondemented elderly controls were studied by scanning electron microscopy in conjunction with X-ray energy spectrometry. Silver impregnation staining with back-scattered electron imaging was used to evaluate the cells for the presence or absence of neurofibrillary tangles prior to the X-ray analysis. Foci of aluminum were detected within the nuclear region of a high percentage of neurofibrillary tangle-bearing cells from the patients with senile dementia as well as the elderly controls. The normal-appearing neurons from both groups were free of detectable aluminum. These studies suggest that the association of aluminum with senile dementia extends to the neuronal level.