TY - JOUR
T1 - Glutamate receptor desensitization and its role in synaptic transmission
AU - Trussell, Laurence O.
AU - Fischbach, Gerald D.
N1 - Funding Information:
We would like to thank Drs. Jonathan Cohen, Meyer Jackson, Edward McCleskey, and Joe Henry Steinbach for helpful dIscussIons. This work was supported by grants from the National Institutes of Health (NSl8458 and NS22828) and by the McDonnell Center for Cellular and Molecular Neurobiology
PY - 1989/8
Y1 - 1989/8
N2 - 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.
AB - 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.
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U2 - 10.1016/0896-6273(89)90034-2
DO - 10.1016/0896-6273(89)90034-2
M3 - Article
C2 - 2576213
AN - SCOPUS:0024713443
SN - 0896-6273
VL - 3
SP - 209
EP - 218
JO - Neuron
JF - Neuron
IS - 2
ER -