title: A closer look at the apparent correlation of structural and functional connectivity in excitable neural networks.
abstract: The relationship between the structural connectivity (SC) and functional connectivity (FC) of neural systems is a central focus in brain network science. It is an open question, however, how strongly the SC-FC relationship depends on specific topological features of brain networks or the models used for describing excitable dynamics. Using a basic model of discrete excitable units that follow a susceptible - excited - refractory dynamic cycle (SER model), we here analyze how functional connectivity is shaped by the topological features of a neural network, in particular its modularity. We compared the results obtained by the SER model with corresponding simulations by another well established dynamic mechanism, the Fitzhugh-Nagumo model, in order to explore general features of the SC-FC relationship. We showed that apparent discrepancies between the results produced by the two models can be resolved by adjusting the time window of integration of co-activations from which the FC is derived, providing a clearer distinction between co-activations and sequential activations. Thus, network modularity appears as an important factor shaping the FC-SC relationship across different dynamic models.
authors.affiliation: Department of Computational Neuroscience, University Medical Center Eppendorf, Hamburg University, Germany.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Messé
authors.affiliation: School of Engineering and Science, Jacobs University Bremen, Germany.
authors.forename: Marc-Thorsten
authors.initials: MT
authors.lastname: Hütt
authors.affiliation: Department of Cognitive Science, University Osnabrück, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: König
authors.affiliation: 1] Department of Computational Neuroscience, University Medical Center Eppendorf, Hamburg University, Germany [2] Department of Health Sciences, Boston University, USA.
authors.forename: Claus C
authors.initials: CC
authors.lastname: Hilgetag
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D006801:Humans; D009415:Nerve Net / Q000502:physiology*; D016571:Neural Networks, Computer