Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Germany.
Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Germany.
Brain Res Bull. 2018 Jan;136:3-16. doi: 10.1016/j.brainresbull.2016.12.013. Epub 2016 Dec 28.
Glutamate is the major excitatory transmitter in the vertebrate brain. After its release from presynaptic nerve terminals, it is rapidly taken up by high-affinity sodium-dependent plasma membrane transporters. While both neurons and glial cells express these excitatory amino acid transporters (EAATs), the majority of glutamate uptake is accomplished by astrocytes, which convert synaptically-released glutamate to glutamine or feed it into their own metabolism. Glutamate uptake by astrocytes not only shapes synaptic transmission by regulating the availability of glutamate to postsynaptic neuronal receptors, but also protects neurons from hyper-excitability and subsequent excitotoxic damage. In the present review, we provide an overview of the molecular and cellular characteristics of sodium-dependent glutamate transporters and their associated anion permeation pathways, with a focus on astrocytic glutamate transport. We summarize their functional properties and roles within tripartite synapses under physiological and pathophysiological conditions, exemplifying the intricate interactions and interrelationships between neurons and glial cells in the brain.
谷氨酸是脊椎动物大脑中的主要兴奋性递质。它从突触前神经末梢释放后，被高亲和力的钠依赖性质膜转运体迅速摄取。虽然神经元和神经胶质细胞都表达这些兴奋性氨基酸转运体（EAATs），但谷氨酸的摄取主要由星形胶质细胞完成，它们将突触释放的谷氨酸转化为谷氨酰胺或将其转化为自身代谢物。星形胶质细胞摄取谷氨酸不仅通过调节谷氨酸对突触后神经元受体的可利用性来调节突触传递，还可以保护神经元免受过度兴奋和随后的兴奋毒性损伤。在本综述中，我们概述了钠依赖性谷氨酸转运体及其相关阴离子渗透途径的分子和细胞特征，重点介绍了星形胶质细胞的谷氨酸转运。我们总结了它们在生理和病理生理条件下三突触中的功能特性和作用，举例说明了大脑中神经元和神经胶质细胞之间复杂的相互作用和相互关系。
