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

@inproceedings{Jahr1990VoltageDO,
  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},
  year={1990}
}
  • C. Jahr, C. Stevens
  • Published in
    The Journal of neuroscience…
    1990
  • 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
NMDA receptors at excitatory synapses in the hippocampus: test of a theory of magnesium block
TLDR
It is concluded that extrasynaptic and subsynaptic NMDA channels both in culture and in situ have identical properties of magnesium block. Expand
Fast and Slow Voltage-Dependent Dynamics of Magnesium Block in the NMDA Receptor: The Asymmetric Trapping Block Model
TLDR
An asymmetric “trapping block” model in which the voltage-independent closing rate constant of the blocked channel is approximately three times that of the unblocked channel accounts quantitatively for all of these phenomena and for responses to action potential waveform clamp. Expand
A model of NMDA receptor-mediated activity in dendrites of hippocampal CA1 pyramidal neurons.
TLDR
These findings support experimental results that implicate NMDA receptor-mediated conductances in the short-term response plasticity of the CA1 hippocampal pyramidal neuron and suggest that dendritic NMDA receptors, by virtue of their voltage-dependency, can interact with a number of voltage-sensitive conductances to increase the dendrite excitatory response during periods of repetitive synaptic activation. Expand
PERMEANT ION AND SUBUNIT DEPENDENCE OF EXTERNAL Mg2+ BLOCK OF NMDA RECEPTORS
N-methyl-D-aspartate (NMDA) receptors are broadly involved in the CNS physiological and pathological processes. The voltage-dependent block by external Mg2+ is a signature characteristic of the NMDAExpand
NMDA receptor activation by spontaneous glutamatergic neurotransmission.
TLDR
Results indicate that NMDA receptors significantly contribute to signaling at rest in the absence of dendritic depolarizations or concomitant AMPA receptor activity. Expand
Kinetics of Mg2+ unblock of NMDA receptors: implications for spike‐timing dependent synaptic plasticity
TLDR
These effects slow the rate of NMDAR channel opening in response to depolarization in a time‐dependent manner such that the slower components of Mg2+ unblock are enhanced during depolarizations at later times after glutamate application, which has important implications for spike‐timing‐dependent synaptic plasticity (STDP). Expand
Properties of NMDA receptor channels in neurons acutely isolated from epileptic (kindled) rats
TLDR
Kindling, an NMDA receptor- dependent form of activity-dependent neuronal plasticity induced in vivo, results in lasting modifications in the function of singleNMDA receptor channels that can be studied in acutely dissociated neurons. Expand
Glycine-independent and subunit-specific potentiation of NMDA responses by extracellular Mg2+
TLDR
Extracellular Mg2+, which blocks NMDA channels in a voltage-dependent manner and increases the receptor's affinity for glycine, is shown here to potentiate NMDA responses at saturating glycine concentrations, suggesting that Mg 2+ may be the physiological agonist acting at the subunit-specific spermine site. Expand
A model of a CA3 hippocampal pyramidal neuron incorporating voltage-clamp data on intrinsic conductances.
TLDR
After these alterations, tonic depolarization of the soma leads to adapting repetitive firing, whereas stimulation of the distal dendrites leads to bursting, and a critical set of parameters concerns the regulation of the pool of intracellular [Ca2+] that interacts with membrane channels (gK(C) and gK(AHP)), particularly in the dendrite. Expand
The effects of neurotransmitters on the integrative properties of spinal neurons in the lamprey.
TLDR
The reduced neuron model provides an experimentally based description of the highly oscillatory and non-linear responses observed during NMDA activation of the spinal neurons involved in the pattern generation of locomotion. Expand
...
1
2
3
4
5
...

References

SHOWING 1-7 OF 7 REFERENCES
A quantitative description of NMDA receptor-channel kinetic behavior
  • C. Jahr, C. Stevens
  • Chemistry, Medicine
  • The Journal of neuroscience : the official journal of the Society for Neuroscience
  • 1990
TLDR
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
Magnesium gates glutamate-activated channels in mouse central neurones
TLDR
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
Glycine potentiates the NMDA response in cultured mouse brain neurons
TLDR
G glycine may facilitate excitatory transmission in the brain through an allosteric activation of the NMDA receptor, and can be observed in outside-out patches as an increase in the frequency of opening of the channels activated by NMDA agonists. Expand
The effects of L-glutamate and its analogues upon the membrane conductance of central murine neurones in culture.
TLDR
The primary effect was depolarization accomplished by an apparent decrease of neurone input conductance (Gm), which favoured the electrogenesis of regenerative potentials that were insensitive to tetrodotoxin. Expand
Voltaae - deoendent block by ‘ Mg 2 + of NMDA iesponses in spinal cbrd neur & es
  • 1984
Voltaae-deoendent block by 'Mg2+ of NMDA iesponses in spinal cbrd neur&es
  • Nature
  • 1984
The effects of L-glutamate
  • 1982