TY - GEN A1 - Tomov, Petar A1 - Pena, Rodrigo F. O. A1 - Roque, Antonio C. A1 - Zaks, Michael A. T1 - Mechanisms of self-sustained oscillatory states in hierarchical modular networks with mixtures of electrophysiological cell types T2 - Frontiers in computational neuroscience N2 - In a network with a mixture of different electrophysiological types of neurons linked by excitatory and inhibitory connections, temporal evolution leads through repeated epochs of intensive global activity separated by intervals with low activity level. This behavior mimics "up" and "down" states, experimentally observed in cortical tissues in absence of external stimuli. We interpret global dynamical features in terms of individual dynamics of the neurons. In particular, we observe that the crucial role both in interruption and in resumption of global activity is played by distributions of the membrane recovery variable within the network. We also demonstrate that the behavior of neurons is more influenced by their presynaptic environment in the network than by their formal types, assigned in accordance with their response to constant current. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 452 KW - self-sustained activity KW - cortical oscillations KW - irregular firing activity KW - hierarchical modular networks KW - cortical network models KW - intrinsic neuronal diversity KW - up-down states KW - chaotic neural dynamics Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407724 ER - TY - JOUR A1 - Zaks, Michael A. A1 - Tomov, Petar T1 - Onset of time dependence in ensembles of excitable elements with global repulsive coupling JF - Physical review : E, Statistical, nonlinear and soft matter physics N2 - We consider the effect of global repulsive coupling on an ensemble of identical excitable elements. An increase of the coupling strength destabilizes the synchronous equilibrium and replaces it with many attracting oscillatory states, created in the transcritical heteroclinic bifurcation. The period of oscillations is inversely proportional to the distance from the critical parameter value. If the elements interact with the global field via the first Fourier harmonics of their phases, the stable equilibrium is in one step replaced by the attracting continuum of periodic motions. Y1 - 2016 U6 - https://doi.org/10.1103/PhysRevE.93.020201 SN - 2470-0045 SN - 2470-0053 VL - 93 PB - American Physical Society CY - College Park ER -