title: Bidirectional scaling of astrocytic metabotropic glutamate receptor signaling following long-term changes in neuronal firing rates.
abstract: Very little is known about the ability of astrocytic receptors to exhibit plasticity as a result of changes in neuronal activity. Here we provide evidence for bidirectional scaling of astrocytic group I metabotropic glutamate receptor signaling in acute mouse hippocampal slices following long-term changes in neuronal firing rates. Plasticity of astrocytic mGluRs was measured by recording spontaneous and evoked Ca²⁺ elevations in both astrocytic somata and processes. An exogenous astrocytic Gq G protein-coupled receptor was resistant to scaling, suggesting that the alterations in astrocyte Ca²⁺ signaling result from changes in activity of the surface mGluRs rather than a change in intracellular G protein signaling molecules. These findings suggest that astrocytes actively detect shifts in neuronal firing rates and adjust their receptor signaling accordingly. This type of long-term plasticity in astrocytes resembles neuronal homeostatic plasticity and might be important to ensure an optimal or expected level of input from neurons.
authors.affiliation: Graduate Program in Neuroscience, University of California Riverside, Riverside, California, United States of America.
authors.forename: Alison X
authors.initials: AX
authors.lastname: Xie
authors.forename: Min-Yu
authors.initials: MY
authors.lastname: Sun
authors.forename: Thomas
authors.initials: T
authors.lastname: Murphy
authors.forename: Kelli
authors.initials: K
authors.lastname: Lauderdale
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Tiglao
authors.forename: Todd A
authors.initials: TA
authors.lastname: Fiacco
mesh_terms: D000200:Action Potentials; D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002450:Cell Communication; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism; D021962:Membrane Microdomains / Q000378:metabolism; D051379:Mice; D009474:Neurons / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D018094:Receptors, Metabotropic Glutamate / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D043562:Receptors, G-Protein-Coupled; D018094:Receptors, Metabotropic Glutamate; C104077:metabotropic glutamate receptor type 1; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D011188:Potassium; D002118:Calcium