The Dynamics of Excitatory Neurotransmission

从我们的感官体验到我们的显性行为，以及在这两者之间发生的所有复杂的认知过程，这些决定我们是谁的潜在生物学，都严重依赖于神经递质谷氨酸。谷氨酸是大脑中最丰富的神经递质，在大脑的快速信息处理中占绝大多数。为了使脑细胞相互交流，谷氨酸通常首先从一个神经元释放到细胞外空间，在那里它可以作用于位于邻近神经元上的受体。为了实现高信噪比的快速高效通信，谷氨酸必须在最初释放后的几毫秒内从细胞外空间去除。这是通过谷氨酸转运体系统完成的，该系统负责将谷氨酸从细胞外空间摄取回神经元和其他支持细胞。理解谷氨酸转运体系统的重要性被广泛接受的观点所强调，即谷氨酸的快速摄取促进了有效的通讯和细胞生长，而过量或长时间的细胞外谷氨酸水平不利于细胞功能和大脑的信息处理。如果谷氨酸转运系统崩溃，我们的记忆、经验和精神敏锐度，以及几乎所有决定我们是谁的东西也会崩溃。

The underlying biology that makes us who we are — from our sensory experiences to our overt behaviours and all of the complex cognitive processing that occurs in between — critically relies on the neurotransmitter glutamate. Glutamate is the brain’s most abundant neurotransmitter and accounts for the large majority of rapid information processing within the brain. For brain cells to communicate with each other, glutamate is typically first released from one neuron into the extracellular space where it can act on receptors that are located on a neighbouring neuron. In order to achieve rapid and efficient communication with a high signal-to-noise ratio, glutamate must be removed from the extracellular space within milliseconds following its initial release. This is accomplished through the glutamate transporter system, which is responsible for the uptake of glutamate from the extracellular space back into neurons and other supporting cells. The importance of understanding the glutamate transporter system is highlighted by the well-accepted view that rapid glutamate uptake promotes effective communication and cellular growth whereas excessive or prolonged levels of extracellular glutamate is detrimental to cellular function and information processing in the brain. If the glutamate transporter system breaks down, so do our memories, our experiences and mental acuity, as well as virtually everything else that makes us who we are.