Effect of Changing Potassium Ion Concentrations on Rat Cerebral Slices In Vitro: A Study During Development

Abstract
Adult rat cerebral cortex slices when incubated in media of increasing K+ concentrations, from 3-20 mM (physiological conditions), exhibited an increase of Ki+ and a decrease of Nai+ and Cli-. This phenomenon appeared at 30 days postnatally, which is fairly late during development. Over 20 mM-K+ (pathological conditions) an intense water uptake was observed together with an increase of Nai- and Cli-. This was observed in both adult and young animals. The results are discussed in relation to the well known properties of glial (Nai-, K+)-ATPase and carbonic anhydrase.