White matter maturation reshapes structural connectivity in the late developing human brain
- 18 October 2010
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 107 (44), 19067-19072
- https://doi.org/10.1073/pnas.1009073107
Abstract
From toddler to late teenager, the macroscopic pattern of axonal projections in the human brain remains largely unchanged while undergoing dramatic functional modifications that lead to network refinement. These functional modifications are mediated by increasing myelination and changes in axonal diameter and synaptic density, as well as changes in neurochemical mediators. Here we explore the contribution of white matter maturation to the development of connectivity between ages 2 and 18 y using high b-value diffusion MRI tractography and connectivity analysis. We measured changes in connection efficacy as the inverse of the average diffusivity along a fiber tract. We observed significant refinement in specific metrics of network topology, including a significant increase in node strength and efficiency along with a decrease in clustering. Major structural modules and hubs were in place by 2 y of age, and they continued to strengthen their profile during subsequent development. Recording resting-state functional MRI from a subset of subjects, we confirmed a positive correlation between structural and functional connectivity, and in addition observed that this relationship strengthened with age. Continuously increasing integration and decreasing segregation of structural connectivity with age suggests that network refinement mediated by white matter maturation promotes increased global efficiency. In addition, the strengthening of the correlation between structural and functional connectivity with age suggests that white matter connectivity in combination with other factors, such as differential modulation of axonal diameter and myelin thickness, that are partially captured by inverse average diffusivity, play an increasingly important role in creating brain-wide coherence and synchrony.Keywords
This publication has 57 references indexed in Scilit:
- Development of Large-Scale Functional Brain Networks in ChildrenPLoS Biology, 2009
- Protracted Developmental Trajectories of GABAA Receptor α1 and α2 Subunit Expression in Primate Prefrontal CortexBiological Psychiatry, 2009
- Predicting human resting-state functional connectivity from structural connectivityProceedings of the National Academy of Sciences of the United States of America, 2009
- Mapping the Structural Core of Human Cerebral CortexPLoS Biology, 2008
- Resting-State Functional Connectivity Reflects Structural Connectivity in the Default Mode NetworkCerebral Cortex, 2008
- The maturing architecture of the brain's default networkProceedings of the National Academy of Sciences of the United States of America, 2008
- Development of distinct control networks through segregation and integrationProceedings of the National Academy of Sciences of the United States of America, 2007
- Axon pruning: an essential step underlying the developmental plasticity of neuronal connectionsPhilosophical Transactions B, 2006
- Modularity and community structure in networksProceedings of the National Academy of Sciences of the United States of America, 2006
- The Human Connectome: A Structural Description of the Human BrainPLoS Computational Biology, 2005