Liauw Jason, Wang Guo-Du, Zhuo Min
Department of Anesthesiology, Washington University Pain Center, Washington University, St. Louis, MO 63110, USA.
Sheng Li Xue Bao. 2003 Aug 25;55(4):373-80.
Glutamatergic synapses are common excitatory chemical connections in mammalian central nervous system. At these synapses, most of baseline synaptic transmission is mediated by glutamate AMPA receptors. NMDA receptors that are sensitive to voltage-dependent magnesium blockade selectively contribute to activity-dependent synaptic plasticity. However, inhibition of NMDA receptors by systemic or local administration of NMDA receptor antagonists produced significant effects on different physiological functions that are not believed to depend on NMDA receptor related synaptic plasticity. Here we show that NMDA receptors contribute to synaptic responses in the anterior cingulate cortex (ACC), a region important for cognitive and other brain functions. The contribution of NMDA receptors became more prominent when synapses are stimulated at higher frequencies. Furthermore, at temperatures more close to physiological brain temperatures, more NMDA receptor mediated responses were recorded as compared to the room temperature. These data suggest a new function for NMDA receptors in the ACC as important postsynaptic receptors involved in synaptic transmission, in particular when cells are firing at high frequencies.
谷氨酸能突触是哺乳动物中枢神经系统中常见的兴奋性化学连接。在这些突触处，大多数基线突触传递由谷氨酸AMPA受体介导。对电压依赖性镁阻断敏感的NMDA受体选择性地参与依赖活动的突触可塑性。然而，通过全身或局部给予NMDA受体拮抗剂抑制NMDA受体，对不同的生理功能产生了显著影响，而这些生理功能被认为不依赖于NMDA受体相关的突触可塑性。在这里，我们表明NMDA受体对前扣带回皮质（ACC）的突触反应有贡献，ACC是一个对认知和其他脑功能很重要的区域。当以更高频率刺激突触时，NMDA受体的贡献变得更加突出。此外，在更接近生理脑温的温度下，与室温相比，记录到更多NMDA受体介导的反应。这些数据表明NMDA受体在ACC中具有新的功能，作为参与突触传递的重要突触后受体，特别是当细胞高频放电时。
