A switch in spike generation as a gateway to neuronal synchronization
Abstract: Synchronous activity of neuronal networks characterizes brain states in health in disease. While network topology is thought to play a major role for rhythm generation, it is currently not understood how small changes in external parameters, like temperature, can induce strongly synchronized states as they are, for example, observed during epileptic seizures. Based on mathematical methods, we here uncover a mechanism that strongly increases network synchronization via moderate alterations in neuron-intrinsic properties. The mechanism relies on a critical transition in cellular dynamics, which has previously not been recognized for its potential to induce drastic changes in synchronization. The critical switch can be induced by a variety of parameters, including temperature, membrane capacitance, leakiness, and changes in potassium concentration. We identify a generic principle of synchronization that provides a new explanation for physiological and pathophysiological switches between synchronous and asynchronous states.