Voltage dependence of NMDA-activated macroscopic conductances predicted by single-channel kinetics

  title={Voltage dependence of NMDA-activated macroscopic conductances predicted by single-channel kinetics},
  author={Craig E. Jahr and Charles F. Stevens},
  booktitle={The Journal of neuroscience : the official journal of the Society for Neuroscience},
  • C. Jahr, C. Stevens
  • Published in
    The Journal of neuroscience…
  • Chemistry, Medicine
The conductance activated in many mammalian CNS neurons by the glutamate analog NMDA is inhibited at hyperpolarized potentials by extracellular magnesium. Whole-cell recordings from hippocampal neurons in culture were used to determine the voltage dependence of the NMDA conductance in the presence of extracellular magnesium concentrations from 1 microM to 10 mM. The conductance-voltage data are well fitted by a gating function derived from rate constants determined in an earlier study of the… Expand
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  • C. Jahr, C. Stevens
  • Chemistry, Medicine
  • The Journal of neuroscience : the official journal of the Society for Neuroscience
  • 1990
Evaluation of the blocking rates over Mg concentrations from 0.2–200 microM indicate that a single “blocking” mechanism cannot account for the short closed states and that a second voltage-dependent but Mg-independent “blocked” state is necessary to explain the data especially at low M g concentrations. Expand
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The voltage dependence of the NMDA receptor-linked conductance appears to be a consequence of the voltage dependenceof the Mg2+ block and its interpretation does not require the implication of an intramembrane voltage-dependent ‘gate’. Expand
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