title: Astroglial networks scale synaptic activity and plasticity.
abstract: Astrocytes dynamically interact with neurons to regulate synaptic transmission. Although the gap junction proteins connexin 30 (Cx30) and connexin 43 (Cx43) mediate the extensive network organization of astrocytes, their role in synaptic physiology is unknown. Here we show, by inactivating Cx30 and Cx43 genes, that astroglial networks tone down hippocampal synaptic transmission in CA1 pyramidal neurons. Gap junctional networking facilitates extracellular glutamate and potassium removal during synaptic activity through modulation of astroglial clearance rate and extracellular space volume. This regulation limits neuronal excitability, release probability, and insertion of postsynaptic AMPA receptors, silencing synapses. By controlling synaptic strength, connexins play an important role in synaptic plasticity. Altogether, these results establish connexins as critical proteins for extracellular homeostasis, important for the formation of functional synapses.
authors.affiliation: Centre National de la Recherche Scientifique Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Collège de France, 75005 Paris, France.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Pannasch
authors.forename: Lydia
authors.initials: L
authors.lastname: Vargová
authors.forename: Jürgen
authors.initials: J
authors.lastname: Reingruber
authors.forename: Pascal
authors.initials: P
authors.lastname: Ezan
authors.forename: David
authors.initials: D
authors.lastname: Holcman
authors.forename: Christian
authors.initials: C
authors.lastname: Giaume
authors.forename: Eva
authors.initials: E
authors.lastname: Syková
authors.forename: Nathalie
authors.initials: N
authors.lastname: Rouach
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000502:physiology*; D000075302:Connexin 30; D018031:Connexin 43; D017630:Connexins; D017629:Gap Junctions; D018698:Glutamic Acid / Q000378:metabolism; D006624:Hippocampus / Q000502:physiology; D051379:Mice; D009415:Nerve Net; D009473:Neuronal Plasticity; D011188:Potassium / Q000378:metabolism; D013569:Synapses; D009435:Synaptic Transmission
chemical_list: D000075302:Connexin 30; D018031:Connexin 43; D017630:Connexins; C100629:Gjb6 protein, mouse; D018698:Glutamic Acid; D011188:Potassium