Lowering the extracellular potassium concentration elicits epileptic activity in neocortical tissue of epileptic patients

The increase in the extracellular potassium concentration ([K(+)](o)) is a well-established model of epilepsy (the so-called high potassium model). Therefore, it is generally accepted that for the prevention of abnormal excitability and seizure generation, increases of [K(+)](o) must be avoided. In this paper, however, we show that on the contrary, a reduction of [K(+)](o) also elicits epileptic activity in brain slices of man.