NCX activity generates spontaneous Ca2+ oscillations in the astrocytic leaflet microdomain

• Published in: Cell calcium (Edinburgh) 2020-03, Vol.86, p.102137-102137, Article 102137
• Main Authors: Héja, László, Kardos, Julianna
• Format: Article
• Language: English
• Subjects: Astrocytic Glu-Na+ symport; Astrocytic leaflet; Ca2+ oscillations; Glu-Na+ symport; Na+/Ca2+ exchange; Synaptic Glu release
• ISSN: 0143-4160; 1532-1991
• DOI: 10.1016/j.ceca.2019.102137

[Display omitted] •Na+ and Ca2+ dynamics were simulated in astrocytic leaflet.•Intrinsic NCX activity alone generates spontaneous Ca2+ oscillations.•NCX-driven Ca2+ oscillations are remarkably stable across different conditions. The synergy between synaptic Glu release and astrocytic Glu-Na+ symport is essential to the signalling function of the tripartite synapse. Here we used kinetic data of astrocytic Glu transporters (EAAT) and the Na+/Ca2+ exchanger (NCX) to simulate Glu release, Glu uptake and subsequent Na+ and Ca2+ dynamics in the astrocytic leaflet microdomain following single release event. Model simulations show that Glu-Na+ symport differently affect intracellular [Na+] in synapses with different extent of astrocytic coverage. Surprisingly, NCX activity alone has been shown to generate markedly stable, spontaneous Ca2+ oscillation in the astrocytic leaflet. These on-going oscillations appear when NCX operates either in the forward or reverse direction. We conjecture that intrinsic NCX activity may play a prominent role in the generation of astrocytic Ca2+ oscillations.