Morita K, Koketsu K, Kuba K
Nature. 1980 Jan 10;283(5743):204-5. doi: 10.1038/283204a0.
The intracellular free Ca2+ ([Ca2+]i) regulates the K+ conductance (GK) of the many types of cell membrane. The Ca2+ influx during an action potential activates this [Ca2+]i-linked GK in most neurones. In caffeine-treated sympathetic ganglion cells, however, Ca2+ released from an intracellular Ca2+ reservoir site analogous to the sarcoplasmic reticulum (SR) of the muscle (see ref. 12) causes activation of the GK, which results in slow oscillatory hyperpolarisations (caffeine hyperpolarisation, C-hyperpolarisation). Such a release of Ca2+ linked to the GK of the membrane seems important for understanding the role of the intracellular organelles in the control of membrane activities of a neurone. We report here the mechanism of the slow oscillatory hyperpolarisations recorded from the bullfrog sympathetic ganglion cell in Ringer solution. It is found that these hyperpolarisations are generated by a [Ca2+]i-linked GK system and are highly sensitive to anions in an intracellular recording electrode, probably to intracellular anions.
细胞内游离钙离子（[Ca2+]i）调节多种细胞膜的钾离子电导（GK）。在大多数神经元中，动作电位期间的钙离子内流激活这种与[Ca2+]i相关的GK。然而，在经咖啡因处理的交感神经节细胞中，从类似于肌肉肌浆网（SR）的细胞内钙离子储存位点释放的钙离子（见参考文献12）会导致GK激活，从而产生缓慢的振荡性超极化（咖啡因超极化，C-超极化）。这种与膜GK相关的钙离子释放似乎对于理解细胞内细胞器在控制神经元膜活动中的作用很重要。我们在此报告在林格氏液中记录到的牛蛙交感神经节细胞缓慢振荡性超极化的机制。发现这些超极化是由一个与[Ca2+]i相关的GK系统产生的，并且在细胞内记录电极中对阴离子高度敏感，可能是对细胞内阴离子敏感。
