title: Lifespan maturation and degeneration of human brain white matter.
abstract: Properties of human brain tissue change across the lifespan. Here we model these changes in the living human brain by combining quantitative magnetic resonance imaging (MRI) measurements of R1 (1/T1) with diffusion MRI and tractography (N=102, ages 7-85). The amount of R1 change during development differs between white-matter fascicles, but in each fascicle the rate of development and decline are mirror-symmetric; the rate of R1 development as the brain approaches maturity predicts the rate of R1 degeneration in aging. Quantitative measurements of macromolecule tissue volume (MTV) confirm that R1 is an accurate index of the growth of new brain tissue. In contrast to R1, diffusion development follows an asymmetric time-course with rapid childhood changes but a slow rate of decline in old age. Together, the time-courses of R1 and diffusion changes demonstrate that multiple biological processes drive changes in white-matter tissue properties over the lifespan.
authors.affiliation: 1] Department of Psychology, Stanford University, Jordan Hall, 450 Serra Mall, Stanford, California 94305, USA [2] Stanford University Center for Cognitive and Neurobiological Imaging, Stanford, California 94305, USA.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Yeatman
authors.affiliation: 1] Department of Psychology, Stanford University, Jordan Hall, 450 Serra Mall, Stanford, California 94305, USA [2] Stanford University Center for Cognitive and Neurobiological Imaging, Stanford, California 94305, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Wandell
authors.affiliation: 1] Department of Psychology, Stanford University, Jordan Hall, 450 Serra Mall, Stanford, California 94305, USA [2] Stanford University Center for Cognitive and Neurobiological Imaging, Stanford, California 94305, USA [3] Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Givat Ram, Jerusalem 91904, Israel.
authors.forename: Aviv A
authors.initials: AA
authors.lastname: Mezer
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001931:Brain Mapping / Q000379:methods*; D002648:Child; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology; D015203:Reproducibility of Results; D066127:White Matter / Q000473:pathology / Q000502:physiology*; D055815:Young Adult