title: Spontaneous Ca2+transients in mouse microglia.
abstract: Microglia are the resident immune cells in the central nervous system and many of their physiological functions are known to be linked to intracellular calcium (Ca2+) signaling. Here we show that isolated and purified mouse microglia-either freshly or cultured-display spontaneous and transient Ca2+elevations lasting for around ten to twenty seconds and occurring at frequencies of around five to ten events per hour and cell. The events were absent after depletion of internal Ca2+stores, by phospholipase C (PLC) inhibition or blockade of inositol-1,4,5-trisphosphate receptors (IP3Rs), but not by removal of extracellular Ca2+, indicating that Ca2+is released from endoplasmic reticulum intracellular stores. We furthermore provide evidence that autocrine ATP release and subsequent activation of purinergic P2Y receptors is not the trigger for these events. Spontaneous Ca2+transients did also occur after stimulation with Lipopolysaccharide (LPS) and in glioma-associated microglia, but their kinetics differed from control conditions. We hypothesize that spontaneous Ca2+transients reflect aspects of cellular homeostasis that are linked to regular and patho-physiological functions of microglia.
authors.affiliation: Max-Delbrueck-Centrum for Molecular Medicine (MDC) in the Helmholtz Association, Cellular Neurosciences, Robert-Roessle-Str. 10, 13092 Berlin, Germany.
authors.forename: Laura
authors.initials: L
authors.lastname: Korvers
authors.affiliation: Max-Delbrueck-Centrum for Molecular Medicine (MDC) in the Helmholtz Association, Cellular Neurosciences, Robert-Roessle-Str. 10, 13092 Berlin, Germany.
authors.forename: Amanda
authors.initials: A
authors.lastname: de Andrade Costa
authors.affiliation: Max-Delbrueck-Centrum for Molecular Medicine (MDC) in the Helmholtz Association, Cellular Neurosciences, Robert-Roessle-Str. 10, 13092 Berlin, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Mersch
authors.affiliation: Max-Delbrueck-Centrum for Molecular Medicine (MDC) in the Helmholtz Association, Cellular Neurosciences, Robert-Roessle-Str. 10, 13092 Berlin, Germany.
authors.forename: Vitali
authors.initials: V
authors.lastname: Matyash
authors.affiliation: Max-Delbrueck-Centrum for Molecular Medicine (MDC) in the Helmholtz Association, Cellular Neurosciences, Robert-Roessle-Str. 10, 13092 Berlin, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Kettenmann
authors.affiliation: Max-Delbrueck-Centrum for Molecular Medicine (MDC) in the Helmholtz Association, Cellular Neurosciences, Robert-Roessle-Str. 10, 13092 Berlin, Germany. Electronic address: marcus.semtner@mdc-berlin.de.
authors.forename: Marcus
authors.initials: M
authors.lastname: Semtner
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*
chemical_list: D008070:Lipopolysaccharides; D002118:Calcium
keywords: Calcium; Endoplasmic reticulum; IP(3) receptor; Microglia; Purinergic receptors; Spontaneous