title: Use of bomb pulse carbon-14 to age senile plaques and neurofibrillary tangles in Alzheimer's disease.
abstract: The time course of formation of neurofibrillary tangles (NFT) and senile plaques (SP) in Alzheimer's disease (AD) brain is unknown. Above ground nuclear weapons testing in the late 1950s and early 1960s led to significantly increased levels of 14C in the atmosphere and carbon cycle. Because the amyloid beta peptide of SP and paired helical filaments of NFT, once formed, are relatively resistant to degradation, 14C levels observed in SP and NFT should reflect their year of formation. The purpose of this study was to develop a method to determine whether 14C levels could be used to define NFT and SP ages. Using accelerator mass spectrometry to measure bomb-pulse 14C levels, we determined the average age of formation of isolated SP and NFT fractions in bulk brain samples of 6 AD subjects. Although preliminary, the results demonstrate that it is possible to use bomb pulse 14C to determine the average year of formation of NFT and SP in the brain in AD. In addition, the data show that these structures, once formed, have a much slower carbon turnover rate than normal brain and are not in a formation/enzymatic degradation equilibrium.
authors.affiliation: From the Sanders-Brown Center on Aging and Alzheimer's Disease Research Center, 101 Sanders-Brown Bldg., University of Kentucky, Lexington 40536-0230, USA. malove2@pop.uky.edu
authors.forename: Mark A
authors.initials: MA
authors.lastname: Lovell
authors.forename: J David
authors.initials: JD
authors.lastname: Robertson
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Buchholz
authors.forename: Chengsong
authors.initials: C
authors.lastname: Xie
authors.forename: William R
authors.initials: WR
authors.lastname: Markesbery
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D000544:Alzheimer Disease / Q000473:pathology*; D001921:Brain / Q000473:pathology; D002250:Carbon Radioisotopes / Q000032:analysis; D002531:Cerebellum / Q000473:pathology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D016874:Neurofibrillary Tangles / Q000473:pathology*; D009689:Nuclear Warfare; D058225:Plaque, Amyloid / Q000473:pathology*; D016622:Silver Staining
chemical_list: D002250:Carbon Radioisotopes