title: Regional brain changes in aging healthy adults: general trends, individual differences and modifiers.
abstract: Brain aging research relies mostly on cross-sectional studies, which infer true changes from age differences. We present longitudinal measures of five-year change in the regional brain volumes in healthy adults. Average and individual differences in volume changes and the effects of age, sex and hypertension were assessed with latent difference score modeling. The caudate, the cerebellum, the hippocampus and the association cortices shrunk substantially. There was minimal change in the entorhinal and none in the primary visual cortex. Longitudinal measures of shrinkage exceeded cross-sectional estimates. All regions except the inferior parietal lobule showed individual differences in change. Shrinkage of the cerebellum decreased from young to middle adulthood, and increased from middle adulthood to old age. Shrinkage of the hippocampus, the entorhinal cortices, the inferior temporal cortex and the prefrontal white matter increased with age. Moreover, shrinkage in the hippocampus and the cerebellum accelerated with age. In the hippocampus, both linear and quadratic trends in incremental age-related shrinkage were limited to the hypertensive participants. Individual differences in shrinkage correlated across some regions, suggesting common causes. No sex differences in age trends except for the caudate were observed. We found no evidence of neuroprotective effects of larger brain size or educational attainment.
authors.affiliation: Department of Psychology and Institute of Gerontology, Wayne State University, 87 East Ferry St, 226 Knapp Building, Detroit, MI 48202, USA. nraz@wayne.edu
authors.forename: Naftali
authors.initials: N
authors.lastname: Raz
authors.forename: Ulman
authors.initials: U
authors.lastname: Lindenberger
authors.forename: Karen M
authors.initials: KM
authors.lastname: Rodrigue
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Kennedy
authors.forename: Denise
authors.initials: D
authors.lastname: Head
authors.forename: Adrienne
authors.initials: A
authors.lastname: Williamson
authors.forename: Cheryl
authors.initials: C
authors.lastname: Dahle
authors.forename: Denis
authors.initials: D
authors.lastname: Gerstorf
authors.forename: James D
authors.initials: JD
authors.lastname: Acker
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001824:Body Constitution / Q000502:physiology*; D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009929:Organ Size / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012737:Sex Factors