Bevan S, Chiu S Y, Gray P T, Ritchie J M
Proc R Soc Lond B Biol Sci. 1985 Sep 23;225(1240):299-313. doi: 10.1098/rspb.1985.0063.
Patch-clamp recording from the plasmalemma of rat cultured astrocytes reveals the presence of both voltage-dependent sodium and voltage-dependent potassium conductances. These conductances are similar but not identical to the corresponding conductances in the axolemma. Whereas the h infinity relation of the sodium channels has the same voltage dependence as in the nodal axolemma, the peak current-voltage relation is shifted by about 30 mV along the voltage axis in the depolarizing direction. It is speculated that the glial cells synthesize sodium and potassium channels for later insertion into the axolemma of neighbouring axons. The astrocytes also express a plasmalemmal voltage-dependent anion conductance that is turned on at about -40 mV (that is, near the resting potential of the cultured astrocytes). The channels involved are large enough to be just permeable to glutamate but not to ascorbate. It is suggested that the conductance of this channel for chloride plays a physiological role in the spatial buffering of potassium by glial cells.
对大鼠培养星形胶质细胞的质膜进行膜片钳记录，发现存在电压依赖性钠电导和电压依赖性钾电导。这些电导与轴膜中的相应电导相似但并不相同。虽然钠通道的h∞关系与结区轴膜中的具有相同的电压依赖性，但峰值电流-电压关系在去极化方向上沿电压轴移动了约30 mV。据推测，神经胶质细胞合成钠通道和钾通道，以便随后插入相邻轴突的轴膜中。星形胶质细胞还表达一种质膜电压依赖性阴离子电导，该电导在约-40 mV（即接近培养的星形胶质细胞的静息电位）时开启。所涉及的通道足够大，刚好可通透谷氨酸盐，但不通透抗坏血酸盐。有人提出，该氯离子通道的电导在神经胶质细胞对钾的空间缓冲中起生理作用。
