Diversity of astrocyte potassium channels: An update

Astrocyte K+ channels and the K+ currents they mediate dwarf all other transmembrane conductances in these cells. This defining feature of astrocytes and its functional implications have been investigated intensely over the past decades. Nonetheless, many aspects of astrocyte K+ handling and signaling remain incompletely understood. In this review, we provide an update on the diversity of K+ channels expressed by astrocytes and new functional implications. We focus on inwardly-rectifying K+ channels (particularly Kir4.1), two-pore K+ channels and voltage and Ca2+-dependent K+ channels. We further discuss new insights into the involvement of these K+ channels in K+ buffering, control of synaptic transmission, regulation of the vasculature and in diseases of the central nervous system.