Neuronal and network dynamics preceding experimental seizures

© 2013 by World Scientific Publishing Co. Pte. Ltd. All rights reserved. How seizures are initiated remains far from clear. Understanding the dynamics of neuronal networks, which lead to transition to seizure, and identifying reliable markers for this process remains an area of active research. Recent studies demonstrated that seizures can be preceded by detectable changes in cellular and network dynamics. These dynamical features resemble a process of critical slowing which is characterized by an increase variance in time series, shift to lower frequencies, increased skewness etc. Additionally, it is accompanied by a progressive decrease of neuronal network resilience, which manifests as enhanced sensitivity to external or internal perturbations. Transition to seizure occurs during a very unstable state of network dynamics when even very weak perturbations are capable of tipping the dynamical regime of the network to seizure. Demonstrating that the dynamics of epileptic neuronal networks are governed by similar principles to other dynamical systems opens new ways to design better methods to examine network dynamical state and to control and/or reverse the transition to seizure.