title: Calcium dynamics in astrocyte processes during neurovascular coupling.
abstract: Enhanced neuronal activity in the brain triggers a local increase in blood flow, termed functional hyperemia, via several mechanisms, including calcium (Ca(2+)) signaling in astrocytes. However, recent in vivo studies have questioned the role of astrocytes in functional hyperemia because of the slow and sparse dynamics of their somatic Ca(2+) signals and the absence of glutamate metabotropic receptor 5 in adults. Here, we reexamined their role in neurovascular coupling by selectively expressing a genetically encoded Ca(2+) sensor in astrocytes of the olfactory bulb. We show that in anesthetized mice, the physiological activation of olfactory sensory neuron (OSN) terminals reliably triggers Ca(2+) increases in astrocyte processes but not in somata. These Ca(2+) increases systematically precede the onset of functional hyperemia by 1-2 s, reestablishing astrocytes as potential regulators of neurovascular coupling.
authors.affiliation: 1] Institut National de la Santé et de la Recherche Médicale (INSERM), U1128, Paris, France. [2] Laboratory of Neurophysiology and New Microscopies, Université Paris Descartes, Paris, France.
authors.forename: Yo
authors.initials: Y
authors.lastname: Otsu
authors.affiliation: 1] Institut National de la Santé et de la Recherche Médicale (INSERM), U1128, Paris, France. [2] Laboratory of Neurophysiology and New Microscopies, Université Paris Descartes, Paris, France.
authors.forename: Kiri
authors.initials: K
authors.lastname: Couchman
authors.affiliation: 1] Institut National de la Santé et de la Recherche Médicale (INSERM), U1128, Paris, France. [2] Laboratory of Neurophysiology and New Microscopies, Université Paris Descartes, Paris, France.
authors.forename: Declan G
authors.initials: DG
authors.lastname: Lyons
authors.affiliation: 1] Centre National de la Recherche Scientifique (CNRS), UMR 7203, Paris, France. [2] Laboratory of Biomolecules, Université Pierre et Marie Curie, Paris, France.
authors.forename: Mayeul
authors.initials: M
authors.lastname: Collot
authors.affiliation: The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Amit
authors.identifier: 0000000179484498
authors.initials: A
authors.lastname: Agarwal
authors.affiliation: 1] Centre National de la Recherche Scientifique (CNRS), UMR 7203, Paris, France. [2] Laboratory of Biomolecules, Université Pierre et Marie Curie, Paris, France.
authors.forename: Jean-Maurice
authors.initials: JM
authors.lastname: Mallet
authors.affiliation: CNRS UPR 3212, University of Strasbourg, Institute of Cellular and Integrative Neurosciences (INCI), Strasbourg, France.
authors.forename: Frank W
authors.initials: FW
authors.lastname: Pfrieger
authors.affiliation: The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Dwight E
authors.initials: DE
authors.lastname: Bergles
authors.affiliation: 1] Institut National de la Santé et de la Recherche Médicale (INSERM), U1128, Paris, France. [2] Laboratory of Neurophysiology and New Microscopies, Université Paris Descartes, Paris, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Charpak
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D009830:Olfactory Bulb / Q000166:cytology / Q000378:metabolism*; D018034:Olfactory Receptor Neurons / Q000378:metabolism / Q000502:physiology*; D064529:Receptor, Metabotropic Glutamate 5 / Q000378:metabolism; D013569:Synapses / Q000378:metabolism*
chemical_list: C578936:Grm5 protein, mouse; D064529:Receptor, Metabotropic Glutamate 5