Voxelwise Mapping of Neuronal Structural Connectivity in Adolescents

Abstract

Longitudinal studies have demonstrated that the white matter in adolescents is still developing well into young adulthood. However, these studies of the corpus callosum were anatomical and DTI studies involving manual region of interest measures, which have not proven to be as in depth of an analysis as the one proposed in this study. In addition, there have been relatively few studies that have looked at the effects of childhood maltreatment on brain structure. The methodology presented here develops a technique that will perform an extensive analysis between a well characterized group of healthy adolescents with no trauma history and a group of maltreated adolescents with PTSD symptoms. It employs a voxelwise analysis to determine significant groups of voxels using cluster enhancement and permutation correction algorithms. It then uses these significant clusters to perform an in-depth ROI analysis to determine the correlations present in these clusters with several physical and neuropsychological measures. This technique has produced evidence that validates earlier studies showing that better executive function and task ability indicate stronger structural organization within the white matter of the brain. In addition, it has provided substantial evidence that maltreated children complete myelination within the corpus callosum of the brain earlier than healthy children, indicating that chronic stress during childhood may be associated with stress-induced premature ageing.