Brain extracellular space changes dynamically during physiological and pathological neuronal activity

Abstract

Brain cells are separated from each other by extracellular space (ECS) that occupies about 20% of tissue volume. It serves both as an ionic reservoir and a channel for diffusion of signaling molecules, metabolites and therapeutic agents. The ECS has traditionally been viewed as static and functionally less significant than neuronal and glial compartments. However, our recent studies indicate that the volume of the ECS changes dynamically in response to physiological and pathologicalneuronal activity, and that these changes have important functional consequences.