Synergistic Effects of Age on Patterns of White and Gray Matter Volume across Childhood and Adolescence

Abstract

The human brain develops with a nonlinear contraction of gray matter across late childhood and adolescence with a concomitant increase in white matter volume. Across the adult population, properties of cortical gray matter covary within networks that may represent organizational units for development and degeneration. Although gray matter covariance may be strongest within structurally connected networks, the relationship to volume changes in white matter remains poorly characterized. In the present study we examined age-related trends in white and gray matter volume using T1-weighted MR images from 360 human participants from the NIH MRI study of Normal Brain Development. Images were processed through a voxel-based morphometry pipeline. Linear effects of age on white and gray matter volume were modeled within four age bins, spanning 4-18 years, each including 90 participants (45 male). White and gray matter age-slope maps were separately entered into k-means clustering to identify regions with similar age-related variability across the four age bins. Four white matter clusters were identified, each with a dominant direction of underlying fibers: anterior–posterior, left–right, and two clusters with superior–inferior directions. Corresponding, spatially proximal, gray matter clusters encompassed largely cerebellar, fronto-insular, posterior, and sensorimotor regions, respectively. Pairs of gray and white matter clusters followed parallel slope trajectories, with white matter changes generally positive from 8 years onward (indicating volume increases) and gray matter negative (decreases). As developmental disorders likely target networks rather than individual regions, characterizing typical coordination of white and gray matter development can provide a normative benchmark for understanding atypical development.

Early childhood development of white matter fiber density and morphology

“…Tract volume (Brouwer et al, 2012;Taki et al, 2013) and fiber cross-section (Genc et al, 2018b(Genc et al, , 2019 have been shown to increase during childhood in most major white matter tracts, with slower increases in the genu of the corpus callosum and uncinate fasciculi (Genc et al, 2018b;Taki et al, 2013); findings that are consistent with our FC results. Our group has also previously shown, in an independent dataset, directional selectivity in age-associations of white matter volumes: a superior-inferior oriented white mater region encompassing the corticospinal tracts showed the largest age-slope in early childhood (Bray et al, 2015). This is consistent with the rapid FC changes in the CST reported here.…”

Multimodal Neuroimaging of Frontolimbic Structure and Function Associated With Suicide Attempts in Adolescents and Young Adults With Bipolar Disorder

“…This study’s data do not permit addressing this possibility. However, reciprocal relationships between neurons and glia during development may contribute to concomitant gray and white matter developmental changes (34–36). It is also possible that gray-white associations are the results of other biological processes, as opposed to a direct interaction between their developmental processes.…”

Maturational Changes in Human Dorsal and Ventral Visual Networks

“…The developmental evidence provided confidence that the age-related gray/white tissue contrast will not negatively influence tissue segmentation in our youngest 6 year-old youngsters since age-related contrasts in gray/white matter after the age of three are no longer noticeable (Barkovich 2000). In addition, the dimensions of the brain, cortical architecture of sulci, gyri, and gray/whitematter contrast are reaching values comparable to adults around the age of 4-5 (Reiss et al 1996;Barkovich 2000Barkovich , 2005Nolte 2008;Bray et al 2015). Although the gray matter thickness was reported to be highest at the age of 4 (Pfefferbaum et al 1994), after the age of 5 no significant age-changes in total cerebral volume were noted (Reiss et al 1996).…”