POTASSIUM CHANNELS IN NODAL AND INTERNODAL AXONAL MEMBRANE OF MAMMALIAN MYELINATED FIBERS
POTASSIUM CHANNELS IN NODAL AND INTERNODAL AXONAL MEMBRANE OF MAMMALIAN MYELINATED FIBERS
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DOI：
10.1038/284170a0
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发表时间：
1980-01-01
期刊：
影响因子：
64.8
通讯作者：
RITCHIE, JM
中科院分区：
文献类型：
--
作者：
CHIU, SY;RITCHIE, JM
Horakova等人第一个观察到青蛙和乌贼神经中钾离子携带的晚期外向电流相位在电压钳制的大鼠Ranvier结中实际上不存在。 Chiuet al.2最近在Ranvier兔淋巴结中证实了这一观察结果，表明哺乳动物的结膜通常具有很少的钾通道（如果有的话）。然而，目前的电压钳实验表明，通过旨在松开轴突膜上的髓磷脂的急性治疗，可以在正常兔朗飞结中产生大的钾电流。由此我们得出结论，虽然哺乳动物结膜中不存在钾通道，但它们通常存在于结间轴突膜中，至少在结旁区域。
Horakovaet al.1were the first to observe that the phase of late outward current carried by potassium ions in frog and squid nerve is virtually absent in voltage-clamped rat nodes of Ranvier. This observation has been recently confirmed by Chiuet al.2in rabbit nodes of Ranvier, suggesting that the nodal membrane in the mammal generally has few if any potassium channels. The present voltage-clamp experiments show that large potassium currents can, however, be produced in normal rabbit nodes of Ranvier by acute treatment designed to loosen the myelin from the axonal membrane. From this we conclude that whereas potassium channels are absent in the mammalian nodal membrane, they are normally present in the internodal axonal membrane at least in the paranodal region.