Potassium dynamics and seizures: Why is potassium ictogenic?

Potassium channels dysfunction and altered genes encoding for molecules involved in potassium homeostasis have been associated with human epilepsy. These observations are in agreement with a control role of extracellular potassium on neuronal excitability and seizure generation. Epileptiform activity, in turn, regulates potassium homeostasis through mechanisms that are still not well established. We review here how potassium-associated processes are regulated in the brain and examine the mechanisms that support the role of potassium in triggering epileptiform activities.