title: Astroglial calcium signaling displays short-term plasticity and adjusts synaptic efficacy.
abstract: Astrocytes are dynamic signaling brain elements able to sense neuronal inputs and to respond by complex calcium signals, which are thought to represent their excitability. Such signaling has been proposed to modulate, or not, neuronal activities ranging from basal synaptic transmission to epileptiform discharges. However, whether calcium signaling in astrocytes exhibits activity-dependent changes and acutely modulates short-term synaptic plasticity is currently unclear. We here show, using dual recordings of astroglial calcium signals and synaptic transmission, that calcium signaling in astrocytes displays, concomitantly to excitatory synapses, short-term plasticity in response to prolonged repetitive and tetanic stimulations of Schaffer collaterals. We also found that acute inhibition of calcium signaling in astrocytes by intracellular calcium chelation rapidly potentiates excitatory synaptic transmission and short-term plasticity of Shaffer collateral CA1 synapses, i.e., paired-pulse facilitation and responses to tetanic and prolonged repetitive stimulation. These data reveal that calcium signaling of astrocytes is plastic and down-regulates basal transmission and short-term plasticity of hippocampal CA1 glutamatergic synapses.
authors.affiliation: Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050 Paris, France ; Université Paris Diderot, Sorbonne Paris Cité Paris, France.
authors.forename: Jérémie
authors.initials: J
authors.lastname: Sibille
authors.affiliation: Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050 Paris, France.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Zapata
authors.affiliation: Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050 Paris, France.
authors.forename: Jérémie
authors.initials: J
authors.lastname: Teillon
authors.affiliation: Neuroglial Interactions in Cerebral Physiopathology, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050 Paris, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Rouach
keywords: calcium signals; glia; hippocampus; neuroglial interactions; neurons; short-term plasticity; synapses; synaptic transmission