Intra-cortical myelination during adolescence
Title: Intra-cortical myelination during adolescence: linking MRI networks with gene transcription profiles
Abstract: Adolescence is a period of human brain growth and high incidence of mental health disorders. The Neuroscience in Psychiatry Network (http://nspn.org.uk) seeks to understand biological underpinnings of the adolescent risk of depression and schizophrenia. In this talk I will present findings using multi-parametric mapping magnetic resonance imaging to measure cortical thickness and intra-cortical myelination in 297 population volunteers aged 14–24 years old [1]. Regional measures at 308 locations across cortex were combined into a structural covariance network and we calculated and extracted topological measures of degree and closeness centrality extracted. All nodal measures were then related to regional gene transcriptome data provided by the Allen Institute for Brain Science (http://human.brain-map.org). We found that association cortical areas were thicker and less myelinated than primary cortical areas at 14 years, but that association cortex had faster rates of shrinkage and myelination over the course of adolescence. Adolescent cortical myelination and shrinkage were coupled and specifically associated with a dorsoventrally patterned gene expression profile enriched for synaptic, oligodendroglial- and schizophrenia-related genes. Topologically efficient and biologically expensive hubs of the brain anatomical network had greater rates of myelination and were associated with overexpression of the same transcriptional profile as cortical consolidation. All results replicated in two independent cohorts. This work demonstrates that measurements of myelin can be linked across the micro and macro scales to better understand typical and atypical adolescent brain development.
[1] Whitaker, K.J., Vértes, P.E., Romero-Garcia, R., Váša, F., Moutoussis, M., Prabhu, G., Weiskopf, N., Callaghan, M.F., Wagstyl, K., Rittman, T., Tait, R., Ooi, C., Suckling, J., Inkster, B., Fonagy, P., Dolan, R.J., Jones, P.B., Goodyer, I.M., NSPN Consortium, Bullmore, E.T., 2016. Adolescence is associated with genomically patterned consolidation of the hubs of the human brain connectome. Proc. Natl. Acad. Sci. USA. 113, 9105–10. doi:10.1073/pnas.1601745113
