The Dynamics of Excitatory Neurotransmission

决定我们是谁的潜在生物学--从我们的感觉体验到我们的公开行为，以及在这两者之间发生的所有复杂的认知过程--关键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，占大脑中快速信息处理的绝大多数。为了让脑细胞相互交流，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邻近神经元上的受体。为了在高信噪比的情况下实现快速、有效的通讯，谷氨酸必须在最初释放后的几毫秒内从细胞外空间中移除。这是通过谷氨酸转运蛋白系统完成的，该系统负责将谷氨酸从细胞外空间吸收回神经元和其他支持细胞。人们普遍认为，快速摄取谷氨酸可促进有效的沟通和细胞生长，而细胞外过多或长时间的谷氨酸水平不利于细胞功能和大脑中的信息处理，这一观点突显了了解谷氨酸转运蛋白系统的重要性。如果谷氨酸转运体系统崩溃，我们的记忆、我们的经历和精神敏锐度也会崩溃，几乎所有造就我们的东西都会崩溃。

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.