Initiation and propagation of activity in neuronal cultures under connectivity alterations

Abstract

Activity in living neuronal networks is governed by complex laws that are still poorly understood. To advance in this quest, we study the initiation and propagation of activity fronts in in vitro neuronal networks. We consider two major experiments in which we modify the connectivity of the network. In a first one, we physically cut a region of the culture. I a second one we apply a drug that changes the connectivity of the network. In both experiments, we determine the velocity of the activity fronts, their timing and the point of origin. We frame our results in the context of the noise focusing phenomena, a mechanism that explains the initiation of activity in terms of network connectivity, neuronal dynamics, and amplification of noise