Potassium Clearance and Reactive Gliosis in the Alumina Gel Lesion

Abstract

K+ accumulation or impaired K+ clearance is hypothesized to contribute to epileptogenesis in gliotic epileptogenic foci. To test this hypothesis, K+ clearance rates following direct cortical stimulation were measured in the cortex of monkeys [Macaca mulatta] rendered epileptic by the injection of alumina gel into the motor area. Reactive gliosis at the sites in which K+ clearance was measured was then quantitated histologically and compared with K+ clearance rates. Dense gliosis was associated with slowed K+ clearance, although the base-line K+ level appeared no different in actively epileptogenic areas or gliotic areas compared with normal areas. Possible mechanisms and significance of slowed K+ clearance in the alumina focus were discussed.