MEMBRANE POTENTIALS IN THE ELECTROPLATES OF THE ELECTRIC EEL
MEMBRANE POTENTIALS IN THE ELECTROPLATES OF THE ELECTRIC EEL
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DOI：
10.1113/jphysiol.1953.sp004849
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发表时间：
1953-01-01
影响因子：
5.5
通讯作者：
MARTINSFERREIRA, H
中科院分区：
文献类型：
--
作者：
KEYNES, RD;MARTINSFERREIRA, H
在电泳器的电镀中，Avg.在24摄氏度下的静息电位为84 mV，细胞的内部相对于外部是负的。在刺激时，神经(后)面产生一个大的棘波，在峰值时，膜电位反转了67 mV。平均。以峰值的一半测量的尖峰持续时间为2.3毫秒。在活动过程中，非神经性面部的电位没有改变，除了电流流过它时产生了几毫伏的被动电压下降。在主要电器官中，膜电位相似，但棘波略小，略短。在活动期间，两个相对表面上的电压加在一起，每个电镀为总放电贡献151 mV(开路)。降温后，棘波显著延长(Q10=2.5)，但幅度变化相对较小。引起神经面的直接(无延迟)反应的条件是施加短暂的去极化。用于超过20毫秒的冲击。临界去极化电压略低于12 mV。尖峰出现在大约一段时间内。全有或全无模式，并观察阈值下刺激的局部反应。神经面的有效电阻为10兆欧厘米~2。在峰值期间它被降低了。非神经性面孔的阻力为0.23兆欧厘米~2。当用等张葡萄糖溶液处理神经面时，动作电位可逆地被取消，而静息电位没有任何大的变化。胆碱喷雾剂。产生了一种不可逆转的不可兴奋性。适用于不紧张的面部，不含钠的鞋底。只是造成了尖峰大小相当缓慢的下降。富钾土壤。在电镀的两面都有去极化效应，这通常是可逆的。当电镀在其末端受到最小冲击的刺激时，它似乎能够以平均速度沿其全长传导脉冲。速度为1.7米/秒。电极板不应被视为改良的运动终板，而应视为特殊适应的肌纤维，其一侧保留了正常的兴奋性膜，而另一侧失去了兴奋性。
In the electroplates of the organ of Sachs of Electrophorus electricus the avg. resting potential at 24[degree] C was 84 mV across each face, the inside of the cell being negative with respect to the outside. On stimulation the nervous (posterior) face produced a large spike, at the peak of which the membrane potential was reversed by 67 mV. The avg. duration of the spike, measured at half its peak amplitude, was 2.3 msec. The potential across the non-nervous face did not alter during activity, except for a passive voltage drop of a few millivolts resulting from the flow of current through it. In the main electric organ the membrane potentials were similar but the spikes were slightly smaller and appreciably shorter. During activity the voltages across the opposite faces added together, each electroplate contributing 151 mV (on open circuit) to the total discharge. On cooling, the spikes were greatly lengthened (Q10 = 2.5) but their amplitude changed relatively little. The condition eliciting the direct (undelayed) response of the nervous face was to apply a brief depolarization. For shocks longer than 20 msec. the critical depolarization was just under 12 mV. The spike arose in an approx. all-or-none fashion, and local responses were observed on subthreshold stimulation. The effective electrical resistance of the nervous face was 10 megohms cm2. It was reduced during the spike. The non-nervous face had a resistance of 0.23 megohms cm2. When the nervous face was treated with an isotonic dextrose soln., the action potential was reversibly abolished without any great change in resting potential. Choline solns. produced an irreversible inexcitability. When applied to the non-nervous face, Na-free solns. only caused a rather slow decline in the size of the spike. K-rich solns. had a depolarizing effect on both faces of the electroplate, which was generally reversible. When an electroplate was stimulated with a minimal shock at its extreme end, it appeared to be capable of conducting an impulse along its whole length at an avg. velocity of 1.7 m./sec. The electroplates should be regarded not as modified motor end-plates, but as specially adapted muscle fibers which have retained a normal excitable membrane on one side and have lost their excitability on the other.