Coordinated brain development: exploring the synchrony between changes in grey and white matter during childhood maturation.

Brain development during childhood and early adolescence is characterized by global changes in brain architecture. Neuroimaging studies have revealed overall decreases in cortical thickness (CT) and increases in fractional anisotropy (FA). Furthermore, previous studies have shown that certain cortical regions display coordinated growth during development. However, there is significant heterogeneity in the timing and speed of these developmental transformations, and it is still unclear whether white and grey matter changes are co-localized. In this multimodal neuroimaging study, we investigated the relationship between grey and white matter developmental changes and asynchronous maturation within brain regions in 249 normally developing children between the ages 7-14. We used structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) to analyze CT and FA, respectively, as well as their covariance across development. Consistent with previous studies, we observed overall cortical thinning with age, which was accompanied by increased FA. We then compared the coordinated development of grey and white matter as indexed by covariance measures. Covariance between grey matter regions and the microstructure of white matter tracts connecting those regions were highly similar, suggesting that coordinated changes in the cortex were mirrored by coordinated changes in their respective tracts. Examining within-brain divergent trajectories, we found significant structural decoupling (decreased covariance) between several brain regions and tracts in the 9- to 11-year-old group, particularly involving the forceps minor and the regions that it connects to. We argue that this decoupling could reflect a developmental pattern within the prefrontal region in 9- and 11-year-old children, possibly related to the significant changes in cognitive control observed at this age.

Inflammation, neurotrophism and oxidative stress and childhood psychopathology in a large community sample.

OBJECTIVE: To investigate the association between peripheral biomarkers and child psychopathology in a large community sample. METHOD: A total of 625 aged 6- to 13-year old subjects were recruited from a community school-based study. Psychopathology was assessed using the Child Behaviour Checklist (CBCL). Psychiatric diagnosis was evaluated using the Development and Well-Being Assessment. The following biomarkers were examined in peripheral blood: brain-derived neurotrophic factor, cytokines (IL-2, IL-4, IL-6, IL-10, IL-17, IFN-g, and TNF-α), chemokines (eotaxin/CCL11, IP-10, MCP-1), cytokine receptors (sTNFR1 and sTNFR2), and the oxidative stress marker TBARS. RESULTS: We found significant associations between sTNFR2, eotaxin/CCL11 and CBCL total score, as well as with specific dimensions of psychopathology. There were different patterns of association between these biomarkers and psychological and behavioural symptoms in children with and without a mental disorder. TBARS, IL-6 and MCP-1 were more specific to some clusters of symptoms in children with a psychiatric diagnosis. CONCLUSION: Our data support the potential use of biomarkers, especially those involved in immune-inflammatory pathways, in investigating neurodevelopmental psychopathology. Their association with different dimensions of symptoms might be of useful when analyzing illness severity and clusters of symptoms within specific disorders.