title: Glutamate-dependent neuroglial calcium signaling differs between young and adult brain.
abstract: An extensive literature shows that astrocytes exhibit metabotropic glutamate receptor 5 (mGluR5)-dependent increases in cytosolic calcium ions (Ca(2+)) in response to glutamatergic transmission and, in turn, modulate neuronal activity by their Ca(2+)-dependent release of gliotransmitters. These findings, based on studies of young rodents, have led to the concept of the tripartite synapse, in which astrocytes actively participate in neurotransmission. Using genomic analysis, immunoelectron microscopy, and two-photon microscopy of astrocytic Ca(2+) signaling in vivo, we found that astrocytic expression of mGluR5 is developmentally regulated and is undetectable after postnatal week 3. In contrast, mGluR3, whose activation inhibits adenylate cyclase but not calcium signaling, was expressed in astrocytes at all developmental stages. Neuroglial signaling in the adult brain may therefore occur in a manner fundamentally distinct from that exhibited during development.
authors: Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA.
authors: Wei
authors: W
authors: Sun
authors: Evan
authors: E
authors: McConnell
authors: Jean-Francois
authors: JF
authors: Pare
authors: Qiwu
authors: Q
authors: Xu
authors: Michael
authors: M
authors: Chen
authors: Weiguo
authors: W
authors: Peng
authors: Ditte
authors: D
authors: Lovatt
authors: Xiaoning
authors: X
authors: Han
authors: Yoland
authors: Y
authors: Smith
authors: Maiken
authors: M
authors: Nedergaard
mesh_terms: D000293:Adolescent; D000375:Aging; D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists / Q000378:metabolism*; D009435:Synaptic Transmission
chemical_list: C578935:GRM5 protein, human; C578936:Grm5 protein, mouse; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate; C102718:metabotropic glutamate receptor 3; D018698:Glutamic Acid; D002118:Calcium