Author/Editor     Kirischuk, Sergei; Parpura, Vladimir; Verkhratsky, Alexei
Title     Sodium dynamics
Type     članek
Vol. and No.     Letnik 35, št. 8
Publication year     2012
Volume     str. 497-506
ISSN     0166-2236 - Trends in neurosciences
Language     eng
Abstract     Astroglial excitability is largely mediated by fluctuations in intracellular ion concentrations. In addition to generally acknowledged Ca2+ excitability of astroglia, recent studies have demonstrated that neuronal activity triggers transient increases in the cytosolic Na+ concentration ([Na+]i) in perisynaptic astrocytes. These [Na+]i transients are controlled by multiple Na+-permeable channels and Na+-dependent transporters; spatiotemporally organized [Na+]i dynamics in turn regulate diverse astroglial homeostatic responses such as metabolic/signaling utilization of lactate and glutamate, transmembrane transport of neurotransmitters and K+ buffering. In particular, near-membrane [Na+]i transients determine the rate and the direction of the transmembrane transport of GABA and Ca2+. We discuss here the role of Na+ in the regulation of various systems that mediate fast bidirectional communication between neurones and glia at the single synapse level.
Keywords     astrocytes
sodium dynamics
Na+/K+ ATPase
Na+/Ca2+ exchanger
glutamate transporter
GABA transporter