Self-organized criticality in the epileptic brain

Criticality is a property of complex dynamical systems that can produce large energy release. Examples in nature of such systems are earthquakes, avalanches and volcanoes. It has been recently demonstrated that networks of integrate-and-fire neurons also exhibit such critical behavior where the system energy is related to the degree of synchronized neuronal firing. We have examined electrographic recordings from human epileptic hippocampus and demonstrate that this tissue exhibits self-organized criticality. These findings may explain energy bursting recently found to occur prior to epileptic seizures in the hippocampus and may connect them to integrate-and-fire models.