Brain Structural Networks Associated with Intelligence and Visuomotor Ability

Increasing evidence indicates that multiple structures in the brain are associated with intelligence and cognitive function at the network level. The association between the grey matter (GM) structural network and intelligence and cognition is not well understood. We applied a multivariate approach to identify the pattern of GM and link the structural network to intelligence and cognitive functions. Structural magnetic resonance imaging was acquired from 92 healthy individuals. Source-based morphometry analysis was applied to the imaging data to extract GM structural covariance. We assessed the intelligence, verbal fluency, processing speed, and executive functioning of the participants and further investigated the correlations of the GM structural networks with intelligence and cognitive functions. Six GM structural networks were identified. The cerebello-parietal component and the frontal component were significantly associated with intelligence. The parietal and frontal regions were each distinctively associated with intelligence by maintaining structural networks with the cerebellum and the temporal region, respectively. The cerebellar component was associated with visuomotor ability. Our results support the parieto-frontal integration theory of intelligence by demonstrating how each core region for intelligence works in concert with other regions. In addition, we revealed how the cerebellum is associated with intelligence and cognitive functions

Developmental changes in organization of structural brain networks

Recent findings from developmental neuroimaging studies suggest that the enhancement of cognitive processes during development may be the result of a fine-tuning of the structural and functional organization of brain with maturation. However, the details regarding the developmental trajectory of large-scale structural brain networks are not yet understood. Here, we used graph theory to examine developmental changes in the organization of structural brain networks in 203 normally growing children and adolescents. Structural brain networks were constructed using interregional correlations in cortical thickness for 4 age groups (early childhood: 4.8-8.4 year; late childhood: 8.5-11.3 year; early adolescence: 11.4-14.7 year; late adolescence: 14.8-18.3 year). Late childhood showed prominent changes in topological properties, specifically a significant reduction in local efficiency, modularity, and increased global efficiency, suggesting a shift of topological organization toward a more random configuration. An increase in number and span of distribution of connector hubs was found in this age group. Finally, inter-regional connectivity analysis and graph-theoretic measures indicated early maturation of primary sensorimotor regions and protracted development of higher order association and paralimbic regions. Our finding reveals a time window of plasticity occurring during late childhood which may accommodate crucial changes during puberty and the new developmental tasks that an adolescent faces

Schizophrenia polygenic risk during typical development reflects multiscale cortical organization

Schizophrenia is widely recognized as a neurodevelopmental disorder, but determining neurodevelopmental features of schizophrenia requires a departure from classic case-control designs. Polygenic risk scoring for schizophrenia (PRS-SCZ) enables investigation of the influence of genetic risk for schizophrenia on cortical anatomy during neurodevelopment and prior to disease onset. PRS-SCZ and cortical morphometry were assessed in typically developing children (3 – 21 years) using T1-weighted MRI and whole genome genotyping (n=390) from the Pediatric Imaging, Neurocognition and Genetics (PING) cohort. Then, we sought to contextualise the findings using (i) age-matched transcriptomics, (ii) gradients of cortical differentiation and (iii) case-control differences of major psychiatric disorders. Higher PRS-SCZ was associated with greater cortical thickness in typically developing children, while surface area and cortical volume showed only subtle associations. Greater cortical thickness was most prominent in areas with heightened gene expression for dendrites and synapses. The pattern of PRS-SCZ associations with cortical thickness reflected functional specialisation in the cortex and was spatially related to cortical abnormalities of patient populations of schizophrenia, bipolar disorder, and major depression. Finally, age interaction models indicated PRS-SCZ effects on cortical thickness were most pronounced between ages 3 and 6, suggesting an influence of PRS-SCZ on cortical maturation early in life. Integrating imaging-genetics with multi-scale mapping of cortical organization, our work contributes to an emerging understanding of how risk for schizophrenia and related disorders manifest in early life

Schizophrenia polygenic risk during typical development reflects multiscale cortical organization

Schizophrenia is widely recognized as a neurodevelopmental disorder, but determining neurodevelopmental features of schizophrenia requires a departure from classic case-control designs. Polygenic risk scoring for schizophrenia (PRS-SCZ) enables investigation of the influence of genetic risk for schizophrenia on cortical anatomy during neurodevelopment and prior to disease onset. PRS-SCZ and cortical morphometry were assessed in typically developing children (3 – 21 years) using T1-weighted MRI and whole genome genotyping (n=390) from the Pediatric Imaging, Neurocognition and Genetics (PING) cohort. Then, we sought to contextualise the findings using (i) age-matched transcriptomics, (ii) gradients of cortical differentiation and (iii) case-control differences of major psychiatric disorders. Higher PRS-SCZ was associated with greater cortical thickness in typically developing children, while surface area and cortical volume showed only subtle associations. Greater cortical thickness was most prominent in areas with heightened gene expression for dendrites and synapses. The pattern of PRS-SCZ associations with cortical thickness reflected functional specialisation in the cortex and was spatially related to cortical abnormalities of patient populations of schizophrenia, bipolar disorder, and major depression. Finally, age interaction models indicated PRS-SCZ effects on cortical thickness were most pronounced between ages 3 and 6, suggesting an influence of PRS-SCZ on cortical maturation early in life. Integrating imaging-genetics with multi-scale mapping of cortical organization, our work contributes to an emerging understanding of how risk for schizophrenia and related disorders manifest in early life