title: Calcium dynamics of cortical astrocytic networks in vivo.
abstract: Large and long-lasting cytosolic calcium surges in astrocytes have been described in cultured cells and acute slice preparations. The mechanisms that give rise to these calcium events have been extensively studied in vitro. However, their existence and functions in the intact brain are unknown. We have topically applied Fluo-4 AM on the cerebral cortex of anesthetized rats, and imaged cytosolic calcium fluctuation in astrocyte populations of superficial cortical layers in vivo, using two-photon laser scanning microscopy. Spontaneous [Ca(2+)](i) events in individual astrocytes were similar to those observed in vitro. Coordination of [Ca(2+)](i) events among astrocytes was indicated by the broad cross-correlograms. Increased neuronal discharge was associated with increased astrocytic [Ca(2+)](i) activity in individual cells and a robust coordination of [Ca(2+)](i) signals in neighboring astrocytes. These findings indicate potential neuron-glia communication in the intact brain.
authors.affiliation: Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, New Jersey, USA. hirase@axon.rutgers.edu
authors.forename: Hajime
authors.initials: H
authors.lastname: Hirase
authors.forename: Lifen
authors.initials: L
authors.lastname: Qian
authors.forename: Peter
authors.initials: P
authors.lastname: Barthó
authors.forename: György
authors.initials: G
authors.lastname: Buzsáki
mesh_terms: D000814:Aniline Compounds / Q000494:pharmacology; D000818:Animals; D001253:Astrocytes / Q000166:cytology* / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002450:Cell Communication; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004594:Electrophysiology; D005260:Female; D005456:Fluorescent Dyes / Q000494:pharmacology; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D018715:Microscopy, Video; D008954:Models, Biological; D009457:Neuroglia / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D014966:Xanthenes / Q000494:pharmacology
chemical_list: D000814:Aniline Compounds; C409648:Fluo 4; D005456:Fluorescent Dyes; D014966:Xanthenes; D002118:Calcium