title: Functional graph alterations in schizophrenia: a result from a global anatomic decoupling?
abstract: During rest, the brain exhibits slow hemodynamic fluctuations (<0.1 Hz) that are correlated across spatially segregated brain regions, defining functional networks. Resting-state functional networks of people with schizophrenia were found to have graph properties that differ from those of control subjects. Namely, functional graphs from patients exhibit reduced small-worldness, increased hierarchy, lower clustering, improved efficiency and greater robustness. Notably, most of these parameters correlate with patients' cognitive performance.To test if a brain-wide coupling deficit could be at the origin of such network reorganization, we use a model of resting-state activity where the coupling strength can be manipulated. For a range of coupling values, the simulated functional graphs obtained were characterized using graph theory.For a coupling range, simulated graphs shared properties of healthy resting-state functional graphs. On decreasing the coupling strength, the resultant functional graphs exhibited a topological reorganization, in the same way as described in schizophrenia.This work shows how complex functional graph alterations reported in schizophrenia can be accounted for by a decrease in the structural coupling strength. These results are corroborated by reports of lower white matter density in schizophrenia.
authors.affiliation: Theoretical and Computational Neuroscience Group, Center for Brain and Cognition, Universitat Pompeu Fabra, Barcelona, Spain. joana.cabral@upf.edu
authors.forename: J
authors.initials: J
authors.lastname: Cabral
authors.forename: M L
authors.initials: ML
authors.lastname: Kringelbach
authors.forename: G
authors.initials: G
authors.lastname: Deco
mesh_terms: D000328:Adult; D000465:Algorithms; D001921:Brain / Q000473:pathology; D016000:Cluster Analysis; D003071:Cognition / Q000502:physiology; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D009415:Nerve Net / Q000473:pathology*; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000473:pathology*; D012565:Schizophrenic Psychology; D055815:Young Adult