Adolescence is associated with genomically patterned consolidation of the hubs of the human brain connectome

TLDR

Adolescence is a critical period of brain growth and high incidence of mental health disorders, during which consolidation of anatomical network hubs may influence normal and disordered development. In two MRI cohorts, adolescent brain changes were concentrated on densely connected hubs that were initially less myelinated but underwent accelerated myelination and cortical shrinkage from ages 14 to 24, a process linked to genes involved in synaptic and myelin functions and schizophrenia risk.

Abstract

Significance Adolescence is a period of human brain growth and high incidence of mental health disorders. Here, we show consistently in two MRI cohorts that human brain changes in adolescence were concentrated on the more densely connected hubs of the connectome (i.e., association cortical regions that mediated efficient connectivity throughout the human brain structural network). Hubs were less myelinated at 14 y but had faster rates of myelination and cortical shrinkage in the 14- to 24-y period. This topologically focused process of cortical consolidation was associated with expression of genes enriched for normal synaptic and myelin-related processes and risk of schizophrenia. Consolidation of anatomical network hubs could be important for normal and clinically disordered adolescent brain development.