Polyadenylated messenger RNA in paired helical filament-immunoreactive neurons in Alzheimer disease

An antibody raised against isolated paired helical filaments (PHF) was used to identify tangle-bearing (PHF⁺) neurons in autopsy brain tissue from six Alzheimer disease (AD) patients and six age-matched controls (AMC). A comparison of the levels of polyadenylated messenger RNA [poly(A)⁺ mRNA] in PHF⁺ and PHF^- neurons of similar cross-sectional area in temporal and parietal lobe and cerebellum from four AD and four AMC brains was made by analysis of in situ hybridization of [³H] polyuridylate [poly(U)] to intracellular poly(A)⁺ mRNA. In PHF⁺ neurons, the level of poly(A)⁺ mRNA was approximately two-thirds that in similar-sized PHF^- neurons in either AD or AMC. The level of poly(A)⁺ mRNA in PHF^- neurons in regions of the brain that have more of the histopathologically defined effects, in AD was similar to that in regions with less effects.