On the Spatial Dynamics of a Network Spike in Neuronal Cultures

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Event Abstract Back to Event On the Spatial Dynamics of a Network Spike in Neuronal Cultures Dmitry Zendrikov1* and Alexander Paraskevov2 1 Moscow Institute of Physics and Technology (State University), Russia 2 National Research Centre "Kurchatov Institute", Russia There exists a short-term (~100 ms), repetitive, spontaneous synchronization of network spiking activity in planar neuronal networks grown in vitro from initially dissociated cortical or hippocampal neurons [1]. Such networks are called neuronal cultures while a single synchronization event is called a network spike (NS) or a population burst. The stationary regime of a NS activity in neuronal cultures is thought to be related to epilepsy therefore both the origin and the properties of such a regime is a subject of intensive studies. In a recent article [2] it was shown experimentally that spatial dynamics of a typical NS is inhomogeneous: there exist a few occasional local sources, or nucleation centers, from which the synchronous spiking activity propagates in the neuronal culture as traveling waves. The number and spatial locations of such sources are unique and steady for the specified culture of excitatory neurons, and these quantities vary over the different cultures. By generalizing the NS simulation model [3] to the case of a spatially-dependent network topology, we show that nucleation centers of a NS occur in simulations at certain conditions. In particular, it is shown that (i) spatial nucleation centers of a network spike appear if the majority of connections between neurons are the local ones, (ii) nucleation centers are not nested in fluctuations of spatial density of neurons, (iii) inhibitory neurons (a) decrease the average frequency of NS occurrence, (b) increase the NS amplitude variability, the NS duration and the number of nucleation centers, (c) do not affect essentially the degree (i.e., coefficient of variation) of periodicity of NSs and the level of spiking activity between the subsequent NSs.