BCAM Scientific Seminar: Spreading Depolarization Happens Spontaneously in models of Epilepsy

Abstract: 
Although spreading depression of brain activity was discovered by Leao in induced seizure experiments, it has rarely been directly observed with spontaneous seizures in the epileptic brain. Recently, spreading depression is shown to underlie sudden unexplained death in epilepsy (SUDEP) in murine models, and assumed without proof to underlie post-ictal generalized suppression.

The physiological underpinning of spreading depression is an electrical spreading depolarization (SD) of brain cells. We developed a recording system for chronic, long-term measurements capable of observing the prolonged (>10s) large (>15mV) and slowly propagating negative deflections in tissue potential that are the hallmark of SD. With it we performed thousands of days of continuous recording, from two very different animal models of epilepsy. We find that SDs are observed with approximately a third of all spontaneous convulsive seizures, and that there are complex interactions between seizures and SDs that may mediate between seizures in clusters.

I-ll describe these findings, our planned efforts to connect these findings with epilepsy-SD unification modeling, and potential relations to neurological co-morbidities.

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