title: Probing scale interaction in brain dynamics through synchronization.
abstract: The mammalian brain operates in multiple spatial scales simultaneously, ranging from the microscopic scale of single neurons through the mesoscopic scale of cortical columns, to the macroscopic scale of brain areas. These levels of description are associated with distinct temporal scales, ranging from milliseconds in the case of neurons to tens of seconds in the case of brain areas. Here, we examine theoretically how these spatial and temporal scales interact in the functioning brain, by considering the coupled behaviour of two mesoscopic neural masses (NMs) that communicate with each other through a microscopic neuronal network (NN). We use the synchronization between the two NM models as a tool to probe the interaction between the mesoscopic scales of those neural populations and the microscopic scale of the mediating NN. The two NM oscillators are taken to operate in a low-frequency regime with different peak frequencies (and distinct dynamical behaviour). The microscopic neuronal population, in turn, is described by a network of several thousand excitatory and inhibitory spiking neurons operating in a synchronous irregular regime, in which the individual neurons fire very sparsely but collectively give rise to a well-defined rhythm in the gamma range. Our results show that this NN, which operates at a fast temporal scale, is indeed sufficient to mediate coupling between the two mesoscopic oscillators, which evolve dynamically at a slower scale. We also establish how this synchronization depends on the topological properties of the microscopic NN, on its size and on its oscillation frequency.
authors.affiliation: Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), Dr. Aiguader 88, 08003 Barcelona, Spain Departament de Fìsica i Enginyeria Nuclear, Universitat Politécnica de Catalunya, Edifici Gaia, Rambla Sant Nebridi 22, 08222 Terrassa, Spain.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Barardi
authors.affiliation: Departament de Fìsica i Enginyeria Nuclear, Universitat Politécnica de Catalunya, Edifici Gaia, Rambla Sant Nebridi 22, 08222 Terrassa, Spain Neuroheuristic Research Group, Faculty of Business and Economics, University of Lausanne, 1015 Lausanne, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Malagarriga
authors.affiliation: Center for Genomic Regulation, Barcelona Biomedical Research Park (PRBB), Dr. Aiguader 88, 08003 Barcelona, Spain.
authors.forename: Belén
authors.initials: B
authors.lastname: Sancristobal
authors.affiliation: Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), Dr. Aiguader 88, 08003 Barcelona, Spain jordi.g.ojalvo@upf.edu.
authors.forename: Jordi
authors.initials: J
authors.lastname: Garcia-Ojalvo
authors.affiliation: Departament de Fìsica i Enginyeria Nuclear, Universitat Politécnica de Catalunya, Edifici Gaia, Rambla Sant Nebridi 22, 08222 Terrassa, Spain.
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Pons
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D003344:Cortical Synchronization / Q000502:physiology*; D006801:Humans; D008959:Models, Neurological; D009415:Nerve Net; D009435:Synaptic Transmission / Q000502:physiology*; D013997:Time Factors
keywords: brain synchronization; conductance-based models; multiscale dynamics; neural mass models