text: Astrocytes express several sAC splice variants, which are involved in metabolic coupling between neurons and astrocytes. Increase of potassium [K] in the extracellular space caused by neuronal activity depolarizes the cell membrane of nearby astrocytes and facilitates the entry of hydrogencarbonate through Na/HCO- cotransporters. The increase in cytosolic hydrogencarbonate activates sAC; the result of this activation is the release of lactate for use as energy source by the neurons.