Quantitative studies of neuronal RNA on the subiculum of demented old individuals.

Autopsied human brains from three patients with senile dementia were studied for the effect of neurofibrillary tangles on neuronal RNA content. Nerve cell bodies were dissected out from the subiculum under the phase contrast microscope and were separated into two groups based on the presence or absence of neurofibrillary tangles within the perikaryon. It was found that the mean RNA content of the tangle-bearing cells was 28.61 pg, whereas that measured in nerve cell bodies considered as free from the tangles was 41.21 pg. Thus, a significant decrease in neuronal RNA content could be correlated to an excess accumulation of neurofibrillary tangles.