THE MECHANISM OF ALPHA-AMINO-3-HYDROXY-5-METHYL-4-ISOXAZOLEPROPIONATE RECEPTOR DESENSITIZATION AFTER REMOVAL OF GLUTAMATE
THE MECHANISM OF ALPHA-AMINO-3-HYDROXY-5-METHYL-4-ISOXAZOLEPROPIONATE RECEPTOR DESENSITIZATION AFTER REMOVAL OF GLUTAMATE
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DOI：
10.1016/s0006-3495(95)80168-2
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发表时间：
1995-01-01
影响因子：
3.4
通讯作者：
TRUSSELL, LO
中科院分区：
文献类型：
--
作者：
RAMAN, IM;TRUSSELL, LO
我们检查了鸡大细胞核中的 AMPA（α-氨基-3-羟基-5-甲基-4-异恶唑丙酸酯）受体对谷氨酸脉冲对的反应，并确定了脱敏程度和恢复率。无论调节脉冲的浓度或持续时间如何，受体以 16 ms 的时间常数从脱敏中恢复。即使使用非常短暂的调节脉冲，引起次最大电流，在去除游离配体后也会以一致的速率发生脱敏。基于这些数据的定量动力学模型表明受体必须从关闭状态脱敏。结果证明，在单量子突触传递的时间尺度上，非常短暂地接触谷氨酸将导致突触后受体的敏感性显着降低。
We have examined responses of AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate) receptors in the chick nucleus magnocellularis to pairs of pulses of glutamate and determined the extent of desensitization and the rate of recovery. Receptors recovered from desensitization with a time constant of 16 ms, regardless of the concentration or duration of the conditioning pulse. Even with very brief conditioning pulses, evoking submaximal currents, desensitization occurred at a consistent rate after the removal of free ligand. A quantitative kinetic model based on these data shows that receptors must desensitize from a closed state. The results provide evidence that very brief exposure to glutamate, on the time scale of uniquantal synaptic transmission, will result in a significant reduction in sensitivity of postsynaptic receptors.