title: Glutamate regulates the frequency of spontaneous synchronized Ca2+ spikes through group II metabotropic glutamate receptor in cultured mouse cortical networks.
abstract: 1. Synchronized spontaneous intracellular Ca2+ spikes in networked neurons are believed to play a major role in the development and plasticity of neural circuits. Glutamate-induced signals through the ionotropic glutamate receptors (iGluRs) are profoundly involved in the generation of synchronized Ca2+ spikes. 2. In this study, we examined the involvement of metabotropic glutamate receptors (mGluRs) in cultured mouse cortical neurons. We pharmacologically revealed that glutamate-induced signals through inclusive mGluRs decreased the frequency of Ca2+ spikes. Further experiments indicated that this suppressive effect on the spike frequency was mainly due to the signal through group II mGluR, inactivation of adenylate cyclase-cAMP-PKA signaling pathway. Group I mGluR had little involvement in the spike frequency. 3. Taken together, glutamate generates the synchronized Ca2+ spikes through iGluRs and modulates simultaneously their frequency through group II mGluR-adenylate cyclase-cAMP-PKA signaling pathway in the present in vitro neural network. These results provide the evidence of the profound role of group II mGluR in the spontaneous and synchronous neural activities.
authors.affiliation: Department of Biomedical Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan. aa37169@mail.ecc.u-tokyo.ac.jp
authors.forename: Fumie
authors.initials: F
authors.lastname: Yasumoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Negishi
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ishii
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kyuwa
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yoshikawa
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology*; D005260:Female; D018698:Glutamic Acid / Q000494:pharmacology* / Q000502:physiology; D051379:Mice; D008813:Mice, Inbred ICR; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology; D011247:Pregnancy; D018091:Receptors, AMPA / Q000819:agonists / Q000502:physiology*
chemical_list: D018091:Receptors, AMPA; D018698:Glutamic Acid; C104722:glutamate receptor ionotropic, AMPA 2