Send to

Choose Destination
See comment in PubMed Commons below
Neuroscientist. 2008 Apr;14(2):171-81. Epub 2007 Oct 18.

Regulation of synaptic transmission by ambient extracellular glutamate.

Author information

  • 1Department of Biological Sciences, University of Illinois at Chicago 60607, USA.


Many neuroscientists assume that ambient extracellular glutamate concentrations in the nervous system are biologically negligible under nonpathological conditions. This assumption is false. Hundreds of studies over several decades suggest that ambient extracellular glutamate levels in the intact mammalian brain are approximately 0.5 to approximately 5 microM. This has important implications. Glutamate receptors are desensitized by glutamate concentrations significantly lower than needed for receptor activation; 0.5 to 5 microM of glutamate is high enough to cause constitutive desensitization of most glutamate receptors. Therefore, most glutamate receptors in vivo may be constitutively desensitized, and ambient extracellular glutamate and receptor desensitization may be potent but generally unrecognized regulators of synaptic transmission. Unfortunately, the mechanisms regulating ambient extracellular glutamate and glutamate receptor desensitization remain poorly understood and understudied.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk