Glutamate Receptor-Mediated Calcium Surges in Neurons Derived from P19 Cells |
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Authors: | Paul Morley Paul MacPherson James F Whitfield †Eric W Harris Michael W McBurney |
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Institution: | Institute for Biological Sciences, National Research Council of Canada, and; Cancer Research Group, Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada;and; Department of Biology, Fisons Pharmaceuticals, Rochester, New York, U.S.A. |
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Abstract: | Abstract: Retinoic acid-treated murine P19 embryonal carcinoma cells differentiate into cells with neuronal morphology that display typical neuronal markers. In this study, the presence of glutamate receptors linked to Ca2+-signaling mechanisms on these neurons was demonstrated by testing the effects of glutamate agonists and antagonists on the intracellular calcium ion concentration (Ca2+]i). Glutamate (1 m M ) induced either sustained or transient increases in Ca2+]i. The sustained glutamate-induced increase in Ca2+]i was mimicked by NMDA (40 µ M ). The NMDA-triggered Ca2+]i response was abolished by incubating the cells in Ca2+-free medium or by pretreating them with Mg2+ (2 m M ) or MK-801 (0.1 µ M ). These responses were unaffected by the non-NMDA antagonist CNQX (10 µ M ), but they required glycine (3–30 µ M ). Kainate (40 µ M ) and AMPA (40 µ M ) did not affect Ca2+]i. Without external Ca2+, glutamate triggered transient, sometimes oscillating, increases in Ca2+]i. These responses were mimicked by the metabotropic agonist trans -(1 S ,3 R )-1-amino-1,3-cyclopentanedicarboxylic acid (300 µ M ). These results suggest that neurons derived from P19 embryonal carcinoma cells have NMDA and metabotropic, but not AMPA/kainate receptors, which are linked to Ca2+-signaling mechanisms. These cells could provide a consistent and reproducible model with which to study neuronal differentiation, neurotoxicity, and glutamate receptor-signaling mechanisms. |
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Keywords: | P19 embryonal carcinoma cells NMDA Glutamate Calcium Kainate-AMPA Metabotropic |
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