Glutamate receptor desensitization and its role in synaptic transmission

Laurence O. Trussell, Gerald D. Fischbach

Research output: Contribution to journalArticlepeer-review

359 Scopus citations


Responses of excitatory amino acid receptors to rapidly applied glutamate were measured in outside-out membrane patches from chick spinal neurons. The peak current varied with glutamate concentration, with a half-maximal response at 510 μM and a Hill coefficient near 2. Currents activated by 1 mM glutamate desensitized and recovered in two phases. The faster time constant was identical to the time constant of decay of synaptic currents, suggesting that glutamatergic synaptic currents are terminated, in part, by receptor desensitization. Steady-state desensitization was evident following application of only 2-3 μM glutamate, concentrations comparable to levels in the extracellular space in the intact brain. Thus, glutamate receptor desensitization can affect synaptic efficacy in two ways: at high concentrations, rapid desensitization of receptors may curtail synaptic currents; at low concentrations, there is a significant reduction in the number of activatable receptors.

Original languageEnglish (US)
Pages (from-to)209-218
Number of pages10
Issue number2
StatePublished - Aug 1989
Externally publishedYes

ASJC Scopus subject areas

  • Neuroscience(all)


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