Blake J F, Brown M W, Collingridge G L
Department of Anatomy, School of Medical Sciences, University of Bristol, U.K.
Neurosci Lett. 1988 Jun 29;89(2):182-6. doi: 10.1016/0304-3940(88)90378-3.
6-Cyano-2,3-dihydroxy-7-nitro-quinoxaline (CNQX; FG 9065) is a new excitatory amino acid antagonist. In the spinal cord it has been reported to selectively block responses to acidic amino acids acting at receptors of the non-N-methyl-D-aspartate (non-NMDA) type. Here we report that in rat hippocampal slices bathed in Mg2+-free medium 10 microM CNQX reversibly blocks responses to alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA), quisqualate and kainate but not NMDA. The synaptic response evoked by low frequency stimulation of Schaffer collateral-commissural fibres in 1 mM Mg2+-containing medium is completely blocked by this concentration of CNQX. In contrast the synaptic response evoked in Mg2+-free medium is not fully blocked by CNQX. The CNQX-insensitive component is, however, abolished by addition of a selective NMDA antagonist. The use of CNQX has allowed for the first time selective synaptic activation of NMDA receptors in the hippocampus.
6-氰基-2,3-二羟基-7-硝基喹喔啉（CNQX；FG 9065）是一种新型兴奋性氨基酸拮抗剂。据报道，在脊髓中它能选择性阻断作用于非N-甲基-D-天冬氨酸（非NMDA）型受体的酸性氨基酸的反应。在此我们报告，在无镁离子培养基中孵育的大鼠海马切片中，10微摩尔的CNQX可可逆性阻断对α-氨基-3-羟基-5-甲基-4-异恶唑丙酸（AMPA）、quisqualate和海人藻酸的反应，但不阻断对NMDA的反应。在含1毫摩尔镁离子的培养基中，低频刺激Schaffer侧支-连合纤维所诱发的突触反应可被该浓度的CNQX完全阻断。相比之下，在无镁离子培养基中诱发的突触反应不能被CNQX完全阻断。然而，加入选择性NMDA拮抗剂后，CNQX不敏感成分被消除。CNQX的应用首次实现了海马中NMDA受体的选择性突触激活。
