Dependence of resting and action potentials on internal potassium in perfused squid giant axons
Dependence of resting and action potentials on internal potassium in perfused squid giant axons
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灌注鱿鱼巨轴突中静息电位和动作电位对内部钾的依赖性
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发表时间：
1963
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通讯作者：
T. Narahashi
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作者：
T. Narahashi
到目前为止，已经进行了几次尝试来改变肌肉纤维和轴突的细胞内离子浓度。这是通过将组织浸泡在无离子或低渗溶液中实现的（Tobias, 1950; Adrian, 1956; Stephenson, 1957； Koketsu和Kimura， 1960），或通过细胞内注射溶液实现的（Grundfest， Kao和Altamirano, 1954； Gibbs和Johnson， 1962）。然而，这些方法不允许人们随意改变细胞内离子组成。还尝试在青蛙肌纤维内部灌注，但该方法不足以令人满意地检查有关的任何问题（Davies, 1961）。最近，两组成功建立了鱿鱼巨轴突细胞内灌注的方法（Oikawa, Spyropoulos, Tasaki & Teorell, 1961; Baker, Hodgkin & Shaw, 1961 a, b）。前一组的方法是通过插入一个大的毛细血管（直径300英寸）来去除轴质，而后一组的方法是通过挤出轴质。最近通过这些方法进行的几项研究已经证明了钠、钾和钙离子在膜电位和兴奋中的重要性（Baker et al. 1961 a, b; Tasaki, 1962; Baker, Hodgkin & Shaw, 1962a, b, c; Tasaki, Watanabe & Takenaka, 1962; Tasaki & Shimamura, 1962）。例如，静息电位通过降低内部钾浓度而降低，而去极化膜仍能产生大振幅的动作电位。提高内钠浓度可降低尖峰高度，但通过调节外钙、镁浓度可在一定程度上恢复尖峰。本研究的目的是双重的。首先，由于两组之前的研究都是在伍兹霍尔进行的，因此试图在体内注入伍兹霍尔平均大小的中型或小型鱿鱼的巨大轴突（直径300-500英寸）
Several attempts have so far been made to change the intracellular concentrations of ions in muscle fibres and axons. This was achieved by soaking tissues in ion-free or hypotonic solutions (Tobias, 1950; Adrian, 1956; Stephenson, 1957; Koketsu & Kimura, 1960), or by injecting solutions intracellularly (Grundfest, Kao & Altamirano, 1954; Gibbs & Johnson, 1962). However, these methods did not allow one to change drastically intracellular ionic compositions at will. An attempt was also made to perfuse the frog muscle fibre internally, but the method was not satisfactory enough to examine any problems concerned (Davies, 1961). Recently successful methods of intracellular perfusion of squid giant axons have been established by two groups (Oikawa, Spyropoulos, Tasaki & Teorell, 1961; Baker, Hodgkin & Shaw, 1961 a, b). The method of the former group depends on removal of axoplasm by inserting a large capillary (300,u in diameter), while that of the latter depends on squeezing out axoplasm. Several recent studies by these methods have demonstrated the importance of sodium, potassium and calcium ions in membrane potential and excitation (Baker et al. 1961 a, b; Tasaki, 1962; Baker, Hodgkin & Shaw, 1962a, b, c; Tasaki, Watanabe & Takenaka, 1962; Tasaki & Shimamura, 1962). For example, the resting potential was decreased by lowering the internal potassium concentration, whereas the depolarized membrane was still able to produce action potentials of large amplitude. Raising the internal sodium concentration decreased the spike height, although the spike could be restored to some extent by adjusting the external calcium and magnesium concentrations. The purpose of the present study is dual. First of all, an attempt was made to perfuse internally medium or small-sized squid giant axons (300-500, in diameter) which were rather of an average size at Woods Hole, since the previous investigations by the two groups were done with