Journal of the American Academy of Child & Adolescent Psychiatry
ColumnsApplied Brain ImagingAnatomical Brain Magnetic Resonance Imaging of Typically Developing Children and Adolescents
Section snippets
Total Cerebral, Cerebellar, and Ventricular Volume
In the Child Psychiatry Branch cohort, total cerebral volume peaks, on average, at 10.5 years in female subjects and 14.5 years in male subjects.1 By age 6 years, the brain is at approximately 95% of this peak (Fig. 1). Cerebellum volume peaks approximately 2 years later than cerebral volume.2 Lateral ventricular volume has the most differences between individuals3 and increases throughout healthy child and adolescent development. These typically occurring increases should be considered when
White Matter
The white color of WM is produced by myelin, fatty white sheaths formed by oligodendrocytes that wrap around axons and drastically increase the speed of neuronal signals. The volume of WM generally increases throughout childhood and adolescence,1 which may underlie greater connectivity and integration of disparate neural circuitry. An important feature that has only recently been appreciated is that myelin does not only maximize speed of transmission but also modulates the timing and synchrony
Gray Matter
Whereas WM increases during childhood and adolescence, the trajectories of GM volumes follow an inverted U—shaped developmental trajectory. The different developmental curves of WM and GM belie the intimate connections among neurons, glial cells, and myelin, which are fellow components in neural circuits and are linked by lifelong reciprocal relations. Cortical GM changes at the voxel level from ages 4 to 20 years derived from scans of 13 subjects who had each been scanned 4 times at
Gene and Environment
By comparing how alike monozygotic twins are versus dizygotic twins, we can estimate the relative contributions of genetic (i.e., “heritability”) and environmental effects to the brain imaging findings.10 Importantly, we can also assess gene-by-environment interactions and the effects of age and sex on heritability. The current sample size from our ongoing longitudinal study is approximately 600 scans from 90 monozygotic and 60 dizygotic twin pairs. Heritability for total cerebrum and lobar
Discussion
The general pattern for typical brain development in the first 25 years of life is a roughly linear increase in WM volumes and regionally specific inverted U—shaped developmental trajectories for GM structures, with peak volumes occurring in late childhood or early adolescence. A prominent theme is that, in neuroimaging, as in life, it is often more about the journey than the destination. This theme is relevant in studies of typical development where there are strong age-by-heritability
References (20)
- et al.
Sexual dimorphism of brain developmental trajectories during childhood and adolescence
Neuroimage
(2007) - et al.
Variability of human brain structure size: ages 4 to 20
Psychiatry Res
(1997) - et al.
A multivariate analysis of neuroanatomic relationships in a genetically informative pediatric sample
Neuroimage
(2007) The NIH MRI study of normal brain development
Neuroimage
(2006)- et al.
Cerebellar development and clinical outcome in attention deficit hyperactivity disorder
Am J Psychiatry
(2007) - et al.
Longitudinal mapping of cortical thickness and brain growth in normal children
J Neurosci
(2004) - et al.
The human brain age 7–11 years: a volumetric analysis based on magnetic resonance images
Cereb Cortex
(1996) - et al.
New insights into neuron-glia communication
Science
(2002) - et al.
Structural maturation of neural pathways in children and adolescents: in vivo study
Science
(1999) - et al.
Dynamic mapping of human cortical development during childhood through early adulthood
Proc Natl Acad Sci U S A
(2004)
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2022, Behavioural Brain ResearchCitation Excerpt :The development of the human brain is a lengthy and complex processes that stretches from a few weeks after conception, into early adulthood. Different neuronal systems and structures mature at a different pace and hence some processes occur early in life while others (e.g., myelination) are only completed in the late 20s [95,98–101]. These neuronal reorganization processes are essential for the maturation of adult behavioral profiles [102], but at the same time render the developing brain susceptible for external and internal disturbances.
This work was supported by the Intramural Research Program of the National Institutes of Health.
The figures in this article were created as part of the authors' employment with the federal government and are therefore in the public domain.