Regional growth trajectories of cortical myelination in adolescents and young adults: longitudinal validation and functional correlates.
Level 3 - non-randomized controlled study
Observational cohort study with cross-sectional and longitudinal neuroimaging analyses.
PubMed 30406353 · doi:10.1007/s11682-018-9980-3
What was done
Cortical myelin content was estimated and harmonized using MRI data from two public datasets: the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA; 226 no-to-low drinking adolescents aged 12–21 years) and the Human Connectome Project (HCP; 686 healthy young adults aged 22–35 years). Age-dependent myelination trajectories were compared between unimodal (primary motor cortex) and multimodal (mid/posterior cingulate cortices) regions, tested for associations with motor task performance in adolescents, and validated using longitudinal MRI data.
What was found
In adolescents, myelin growth trajectories were steeper in the primary motor cortex and flatter in the mid/posterior cingulate cortices. Young adults showed continued myelination but with smaller gains across age. Motor task performance in adolescents correlated with myelin content in motor and cingulate cortices, and regional trajectory slopes were confirmed longitudinally. The abstract reports no numerical values, effect sizes, or test statistics.
Why it matters
This study demonstrates that regional cortical myelination continues through adolescence into young adulthood, following developmental patterns that differ by circuit complexity and correlating with behavioral maturation.
Limits
The abstract reports no numerical values, exact effect sizes, or specific sample sizes for the longitudinal subset. Cortical myelin is estimated indirectly from MRI rather than measured histologically, and findings in healthy or low-drinking samples may not generalize to other populations.
Cited by
- supports Synaptic pruning and myelination continue through adolescence until approximately age 25 to establish adult neural circuitry.