Evolution of white matter tract microstructure across the life span

• Published in: Human brain mapping Vol. 40; no. 7; pp. 2252 - 2268
• Main Authors: Slater, David A., Melie‐Garcia, Lester, Preisig, Martin, Kherif, Ferath, Lutti, Antoine, Draganski, Bogdan
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.05.2019
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Aging; Brain; Brain - diagnostic imaging; Brain - physiology; Child; Cognition; degeneration; development; Diffusion Tensor Imaging - trends; Divergence; Female; Heterogeneity; Humans; intracellular volume fraction (ICVF); iron; Life span; Longevity - physiology; longitudinal (R1) and transverse (R2) relaxation rates; Male; Maturation; mean diffusivity (MD); Microstructure; Middle Aged; MRI; Myelin; Neuroimaging; quantitative magnetic resonance imaging (qMRI); Spatial heterogeneity; Substantia alba; Tissues; tractography; white matter; White Matter - diagnostic imaging; White Matter - physiology; Young Adult; myelin; development; MRI; intracellular volume fraction (ICVF); life span; quantitative magnetic resonance imaging (qMRI); degeneration; mean diffusivity (MD); white matter; tractography; iron; longitudinal (R1) and transverse (R2) relaxation rates; aging
• ISSN: 1065-9471; 1097-0193
• DOI: 10.1002/hbm.24522

The human brain undergoes dramatic structural change over the life span. In a large imaging cohort of 801 individuals aged 7–84 years, we applied quantitative relaxometry and diffusion microstructure imaging in combination with diffusion tractography to investigate tissue property dynamics across the human life span. Significant nonlinear aging effects were consistently observed across tracts and tissue measures. The age at which white matter (WM) fascicles attain peak maturation varies substantially across tissue measurements and tracts. These observations of heterochronicity and spatial heterogeneity of tract maturation highlight the importance of using multiple tissue measurements to investigate each region of the WM. Our data further provide additional quantitative evidence in support of the last‐in‐first‐out retrogenesis hypothesis of aging, demonstrating a strong correlational relationship between peak maturational timing and the extent of quadratic measurement differences across the life span for the most myelin sensitive measures. These findings present an important baseline from which to assess divergence from normative aging trends in developmental and degenerative disorders, and to further investigate the mechanisms connecting WM microstructure to cognition.