The multiscale topological organization of the functional brain network in adolescent PTSD

Abstract

The experience of an extremely aversive event can produce enduring deleterious behavioral and neural consequences, among which posttraumatic stress disorder (PTSD) is a representative example. In this work, we aim to study the whole-cortex functional organization of adolescents with PTSD without the a priori selection of specific regions of interest or functional networks. To do so, we built on the network neuroscience framework and specifically on multisubject community analysis to study the functional connectivity of the brain. We show, across different topological scales (the number of communities composing the cortex), an increased coupling between regions belonging to unimodal (sensory) regions and a reduced coupling between transmodal (association) regions in the adolescent PTSD group. These results open up an intriguing possibility concerning an altered large-scale cortical organization in adolescent PTSD. Significance StatementThe understanding of brain responses following the experience of a traumatic event and the eventual apparition of posttraumatic stress disorder (PTSD) symptoms during youth remains an active topic of research in clinical neuroscience. We adapted a multisubject community detection algorithm to study the functional brain organization of PTSD from a whole cortex and multiscale topological perspective, thereby taking into account the complex (network) organization of the brain. PTSD patients and control subjects presented a different whole cortex functional organization that remained present across topological scales. PTSD patients showed a decreased interaction in transmodal cortices and, inversely, an enhanced interaction in unimodal cortices. This investigation highlights the importance of studying the brain from a complex and whole cortex perspective.