Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1984 May;309(5965):261-3.
doi: 10.1038/309261a0.

Voltage-dependent block by Mg2+ of NMDA responses in spinal cord neurones

M L Mayer, G L Westbrook, P B Guthrie

Voltage-dependent block by Mg2+ of NMDA responses in spinal cord neurones

M L Mayer et al. Nature. 1984 May.

Abstract

Acidic amino acids are putative excitatory synaptic transmitters, the ionic mechanism of which is not well understood. Recent studies with selective agonists and antagonists suggest that neurones of the mammalian central nervous system possess several different receptors for acidic amino acids, which in turn are coupled to separate conductance mechanisms. N-methyl-D-aspartic acid (NMDA) is a selective agonist for one of these receptors. The excitatory action of amino acids acting at NMDA receptors is remarkably sensitive to the membrane potential and it has been suggested that the NMDA receptor is coupled to a voltage-sensitive conductance. Recently, patch-clamp experiments have shown the voltage-dependent block by Mg2+ of current flow through ion channels activated by L-glutamate. We now show using voltage-clamp experiments on mouse spinal cord neurones that the voltage-sensitivity of NMDA action is greatly reduced on the withdrawal of physiological concentrations (approximately 1 mM) of Mg2+ from the extracellular fluid. This provides further evidence that Mg2+ blocks inward current flow through ion channels linked to NMDA receptors.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types

LinkOut - more resources