Ionic Signalling in Neuronal-Astroglial Interactions

The name astroglia unifies many non-excitable neural cells that act as primary homeostatic cells in the nervous system. Neuronal activity triggers multiple homeostatic responses of astroglia that include increase in metabolic activity and synthesis of neuronal preferred energy substrate lactate, clearance of neurotransmitters and buffering of extracellular K⁺ ions to name but a few. Many (if not all) of astroglial homeostatic responses are controlled by dynamic changes in the cytoplasmic concentration of two cations, Ca²⁺ and Na⁺. Intracellular concentration of these ions is tightly controlled by several transporters and can be rapidly affected by activation of respective fluxes through ionic channels or ion exchangers. Here we provide a comprehensive review of astroglial Ca²⁺ and Na⁺ signalling.