Sontheimer H, Black J A, Waxman S G
Neurobiology Research Center, University of Alabama at Birmingham 35294-0021, USA.
Trends Neurosci. 1996 Aug;19(8):325-31. doi: 10.1016/0166-2236(96)10039-4.
Glial cells are nervous-system cells that have classically been considered to be inexcitable. Despite their lack of electrical excitability, they can express voltage-activated Na+ channels with properties similar to the Na+ channels used by excitable cells to generate action potentials. The functional role that these voltage-activated Na+ channels play in glia is unclear. Three functions have been proposed: (1) glial cells might synthesize Na+ channels and donate them to adjacent neurons, thereby reducing the biosynthetic load of neurons; (2) Na+ channels might endow glial cells with the ability to sense electric activity of neighboring neurons, and might thus play a role in neuro-glial communication; and (3) Na+ influx through voltage-gated Na+ channels could be important to fuel the glial (Na+,K+)-ATPase, thereby facilitating and possibly modulating K+ uptake from the extracellular space.
神经胶质细胞是传统上被认为不可兴奋的神经系统细胞。尽管它们缺乏电兴奋性，但它们可以表达电压激活的Na⁺通道，其特性类似于可兴奋细胞用于产生动作电位的Na⁺通道。这些电压激活的Na⁺通道在神经胶质细胞中所起的功能作用尚不清楚。已提出三种功能：（1）神经胶质细胞可能合成Na⁺通道并将其捐赠给相邻神经元，从而减轻神经元的生物合成负担；（2）Na⁺通道可能赋予神经胶质细胞感知相邻神经元电活动的能力，因此可能在神经胶质细胞通讯中发挥作用；（3）通过电压门控Na⁺通道的Na⁺内流对于为神经胶质细胞的（Na⁺，K⁺）-ATP酶提供能量可能很重要，从而促进并可能调节从细胞外空间摄取K⁺。
