title: Physiological neuronal decline in healthy aging human brain - An in vivo study with MRI and short echo-time whole-brain (1)H MR spectroscopic imaging.
abstract: Knowledge of physiological aging in healthy human brain is increasingly important for neuroscientific research and clinical diagnosis. To investigate neuronal decline in normal aging brain eighty-one healthy subjects aged between 20 and 70years were studied with MRI and whole-brain (1)H MR spectroscopic imaging. Concentrations of brain metabolites N-acetyl-aspartate (NAA), choline (Cho), total creatine (tCr), myo-inositol (mI), and glutamine+glutamate (Glx) in ratios to internal water, and the fractional volumes of brain tissue were estimated simultaneously in eight cerebral lobes and in cerebellum. Results demonstrated that an age-related decrease in gray matter volume was the largest contribution to changes in brain volume. Both lobar NAA and the fractional volume of gray matter (FVGM) decreased with age in all cerebral lobes, indicating that the decreased NAA was predominantly associated with decreased gray matter volume and neuronal density or metabolic activity. In cerebral white matter Cho, tCr, and mI increased with age in association with increased fractional volume, showing altered cellular membrane turn-over, energy metabolism, and glial activity in human aging white matter. In cerebellum tCr increased while brain tissue volume decreased with age, showing difference to cerebral aging. The observed age-related metabolic and microstructural variations suggest that physiological neuronal decline in aging human brain is associated with a reduction of gray matter volume and neuronal density, in combination with cellular aging in white matter indicated by microstructural alterations and altered energy metabolism in the cerebellum.
authors.affiliation: Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany. Electronic address: ding.xiaoqi@mh-hannover.de.
authors.forename: Xiao-Qi
authors.initials: XQ
authors.lastname: Ding
authors.affiliation: Department of Radiology, University of Miami School of Medicine, Miami, FL, USA.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Maudsley
authors.affiliation: Department of Radiology, University of Miami School of Medicine, Miami, FL, USA; Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Sabati
authors.affiliation: Department of Radiology, University of Miami School of Medicine, Miami, FL, USA.
authors.forename: Sulaiman
authors.initials: S
authors.lastname: Sheriff
authors.affiliation: Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany.
authors.forename: Birte
authors.initials: B
authors.lastname: Schmitz
authors.affiliation: Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Schütze
authors.affiliation: Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany.
authors.forename: Paul
authors.initials: P
authors.lastname: Bronzlik
authors.affiliation: Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, Hannover, Germany.
authors.forename: Kai G
authors.initials: KG
authors.lastname: Kahl
authors.affiliation: Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Lanfermann
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism* / Q000473:pathology*; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000378:metabolism*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D057054:Molecular Imaging / Q000379:methods; D066244:Proton Magnetic Resonance Spectroscopy / Q000379:methods*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D066127:White Matter / Q000033:anatomy & histology / Q000378:metabolism; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001224:Aspartic Acid; C000179:N-acetylaspartate
keywords: Choline (Cho); Glutamate (Glu); Glutamine (Gln); Myo-inositol (mI); N-acetyl-aspartate (NAA); Neuronal metabolic activity; Normal aging; Total creatine (tCr); Whole-brain MR spectroscopic imaging