Assessing structural organization and functional interaction in gyral, sulcal and cortical networks

Literature studies showed that the fibers connected to gyri are significantly denser than those connected to sulci. Therefore, we hypothesize that gyral, sulcal and cortical brain networks might exhibit different graph properties and functional interactions that reflect the organizational principles of cortical architecture. In this way, we evaluated the graphical properties of the structural brain networks and the functional connectivities among brain networks which are composed of gyral regions of interest (ROI) (G-networks), sulcal ROIs (S-networks) and mixed gyral and sulcal ROIs (C-networks). The results demonstrated that G-networks have the highest global and local economical properties and the strongest small-worldness. In contrast, S-networks have the lowest global and local economical properties and the weakest small-worldness. Meanwhile, the overall functional connectivity strength among G-networks is stronger than those in S-networks, and those in C-networks are in between. The results indicate that gyri may play a hub role in human brains.