The genetics of spatiotemporal variation in cortical thickness in youth

Prior studies have shown strong genetic effects on cortical thickness
(CT), structural covariance, and neurodevelopmental trajectories in
childhood and adolescence. However, the importance of genetic factors on
the induction of spatiotemporal variation during neurodevelopment remains
poorly-understood. Here, we explore the genetics of maturational coupling
by examining 308 MRI-derived regional CT measures in a longitudinal sample
of 677 twins and family members. We find dynamic inter-regional genetic
covariation in youth, with the emergence of regional subnetworks in late
childhood and early adolescence. Three critical neurodevelopmental epochs
in genetically-mediated maturational coupling were identified, with
dramatic network strengthening near eleven years of age. These changes are
associated with statistically-significant (empiric p-value <0.0001)
increases in network strength as measured by average clustering
coefficient and assortativity.  We then identify genes from the
Allen Human Brain Atlas with similar co-expression patterns to
genetically-mediated structural covariation in children. This set was
enriched for genes involved in potassium transport and dendrite formation.
Genetically-mediated CT-CT covariance was also strongly correlated with
expression patterns for genes located in cells of neuronal
origin.