Brain Maturation in Adolescence and Young Adulthood: Regional Age-Related Changes in Cortical Thickness and White Matter Volume and Microstructure

• Published in: Cerebral cortex (New York, N.Y. 1991) Vol. 20; no. 3; pp. 534 - 548
• Main Authors: Tamnes, Christian K., Østby, Ylva, Fjell, Anders M., Westlye, Lars T., Due-Tønnessen, Paulina, Walhovd, Kristine B.
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01.03.2010
• Subjects: Adolescent; Adult; Aging - physiology; Brain Mapping; cerebral cortex; Cerebral Cortex - anatomy & histology; Cerebral Cortex - growth & development; Child; Child Development - physiology; cortical thinning; development; diffusion; Diffusion Magnetic Resonance Imaging - methods; Female; Humans; Imaging, Three-Dimensional - methods; Longitudinal Studies; Male; MRI; Nerve Fibers, Myelinated; Young Adult; cerebral cortex; development; diffusion; MRI; cortical thinning
• ISSN: 1047-3211; 1460-2199
• DOI: 10.1093/cercor/bhp118

The development of cortical gray matter, white matter (WM) volume, and WM microstructure in adolescence is beginning to be fairly well characterized by structural magnetic resonance imaging (sMRI) and diffusion tensor imaging (DTI) studies. However, these aspects of brain development have rarely been investigated concurrently in the same sample and hence the relations between them are not understood. We delineated the age-related changes in cortical thickness, regional WM volume, and diffusion characteristics and investigated the relationships between these properties of brain development. One hundred and sixty-eight healthy participants aged 8–30 years underwent sMRI and DTI. The results showed regional age-related cortical thinning, WM volume increases, and changes in diffusion parameters. Cortical thickness was the most strongly age-related parameter. All classes of measures showed unique associations with age. The results indicate that cortical thinning in adolescence cannot be explained by WM maturation in underlying regions as measured by volumetry or DTI. Moderate associations between cortical thickness and both volume and diffusion parameters in underlying WM regions were also found, although the relationships were not strong. It is concluded that none of the measures are redundant and that the integration of the 3 will yield a more complete understanding of brain maturation.