Hill D A, Sherebrin M H
Can J Physiol Pharmacol. 1976 Aug;54(4):485-93. doi: 10.1139/y76-068.
A decrease in amplitude and conduction speed in the compound action potential is observed with time in gar olfactory and rabbit vagus nerve when it is stimulated between 4 and 15 Hz at 26 degrees C in vitro. The amplitude decays exponentially for 1-3 min before reaching a steady state. Recs 15 s for gar olfactory nerve and 50 s for rabbit vagus nerve. The steady state values are 14% and 36% of the original amplitude, respectively, and conduction speeds are reduced by 25 % in both nerves. The effect results from completion between ion flow during the action potential and active transport. The accumulation of K+ions and depletion of Na+ ions in the restricted extracellular space contributes to the amplitude fatigue while the depletion of Na+ ions alone causes the decrease in conduction speed. Ouabain increases the fatigue rate in both preparations, but more so for gar. The fatigue and recovery measurements may provide a useful method to investigate active pumping, including both the total pumping rate and the electrogenic component.
在体外26摄氏度下，当以4至15赫兹的频率刺激时，可观察到蟾鱼嗅神经和兔迷走神经的复合动作电位的幅度和传导速度随时间下降。在达到稳态之前，幅度呈指数衰减1至3分钟。蟾鱼嗅神经的恢复时间为15秒，兔迷走神经为50秒。稳态值分别为原始幅度的14%和36%，两条神经的传导速度均降低25%。这种效应是由动作电位期间的离子流动与主动转运之间的竞争导致的。受限细胞外空间中K⁺离子的积累和Na⁺离子的消耗导致幅度疲劳，而仅Na⁺离子的消耗导致传导速度下降。哇巴因增加了两种标本的疲劳速率，但对蟾鱼的影响更大。疲劳和恢复测量可能为研究主动泵浦提供一种有用的方法，包括总泵浦速率和生电成分。
