Sodium fluxes and astroglial function

Abstract

Astrocytes exhibit their excitability based on variations in cytosolic Ca2+ levels, which leads to variety of signalling events. Only recently, however, intracellular fluctuations of more abundant cation Na + are brought in the limelight of glial signalling. Indeed, astrocytes possess several plasmalemmal molecular entities that allow rapid transport of Na+ across the plasma membrane: (1) ionotropic receptors, (2) canonical transient receptor potential cation channels, (3) neurotransmitter transporters and (4) sodium-calcium exchanger. Concerted action of these molecules in controlling cytosolic Na+ may complement Ca2+ signalling to provide basis for complex bidirectional astrocyte-neurone communication at the tripartite synapse. © Springer Science+Business Media New York 2013.