title: NMDA receptor-mediated calcium entry in the absence of AMPA receptor activation in rat dorsal horn neurons.
abstract: This study tested quantitatively the degree to which selective activation of NMDA receptors increases the intracellular concentration of free Ca2+ ions ([Ca2+]i) in neurons isolated from the rat spinal cord dorsal horn and grown in culture. The results show that activation of NMDA receptors, without additional depolarizing stimuli, produce [Ca2+]i increases in the neuronal cell bodies in the presence of physiological concentrations of Mg2+. Furthermore, this phenomenon occurs during synaptic activation of NMDA receptors. Thus, it cannot be assumed that in physiological extracellular [Mg2+], there is an absolute requirement for additional membrane depolarization before NMDA receptor activation stimulates significant increases in [Ca2+]i.
authors.affiliation: Department of Physiology and Cellular Biophysics, Columbia University, College of Physicians and Surgeons, New York 10032, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Reichling
authors.forename: A B
authors.initials: AB
authors.lastname: MacDermott
mesh_terms: D000818:Animals; D001711:Biotransformation / Q000502:physiology; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism / Q000502:physiology; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D018091:Receptors, AMPA / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism*; D013569:Synapses / Q000502:physiology
chemical_list: D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D008274:Magnesium; D002118:Calcium