Role of Glial Cells in Seizures and Epilepsy: Intracellular Calcium Oscillations sn Spatial Buffering

Abstract

Spatial Buffering During Slow and Paroxysmal Sleep Oscillations in Cortical Networks of Glial Cells In VivoAmzica F, Massimini M, Manfridi AJ Neurosci 2002;22:1042–1053The ability of neuroglia to buffer local increases of extracellular K+ has been known from in vitro studies. This property may confer on these cells an active role in the modulation and spreading of cortical oscillatory activities. We addressed the question of the spatial buffering in vivo by performing single and double intraglial recordings, together with measures of the extracellular K+ and Ca2+ concentrations ([K+]out and [Ca2+]out) in the cerebral cortex of cats under ketamine and xylazine anesthesia during patterns of slow sleep oscillations and spike-wave seizures. In addition, we estimated the fluctuations of intraglial K+ concentrations ([K+]in). Measurements obtained during the slow oscillation indicated that glial cells phasically take up part of the extracellular K+ extruded by neurons during the depolarizing phase of the slow o...