Radicheva N, Gerilovsky L, Gydikov A
Acta Physiol Pharmacol Bulg. 1986;12(1):26-35.
The changes in the time and space derivatives of the intracellular action potentials of isolated frog muscle fibers immersed in hypertonic sucrose-Ringer's solution were studied using paired stimulation with different interstimulus intervals. The peak-to-peak amplitude and the amplitudes of the separate phases of delta V/delta t and delta 2V/delta t2 decreased at intervals shorter than 10.25 ms as the duration of the phases lengthened. The velocity of spreading decreased at intervals below 7-10 ms and increased at longer intervals up to 40-100 ms. The peak-to-peak amplitude and the amplitudes of the separate phases of delta V/delta x and delta 2V/delta x2 decreased at intervals below 40-100 ms. The length of the separate phases of the space derivatives was almost constant. The extracellular action potentials near the membrane were similar to delta 2V/delta x2. When changing the interstimulus intervals the amplitude of the potentials recorded at different radial distances changed almost proportionally. In normal Ringer's solution the extracellular action potentials at different radial distances also changed almost proportionally depending on the intervals. They decreased at the shortest intervals and increased above the level measured at single stimuli for intervals longer than 7-10 ms, but shorter than 40-100 ms.
使用不同刺激间隔的成对刺激，研究了浸泡在高渗蔗糖 - 林格氏溶液中的离体青蛙肌肉纤维细胞内动作电位的时空导数变化。当刺激间隔短于10.25毫秒时，随着各阶段持续时间延长，峰峰值幅度以及δV/δt和δ2V/δt2各单独阶段的幅度均降低。当刺激间隔低于7 - 10毫秒时，传播速度降低；而当刺激间隔延长至40 - 100毫秒时，传播速度增加。当刺激间隔低于40 - 100毫秒时，δV/δx和δ2V/δx2各单独阶段的峰峰值幅度以及幅度均降低。空间导数各单独阶段的长度几乎恒定。膜附近的细胞外动作电位类似于δ2V/δx2。改变刺激间隔时，在不同径向距离记录的电位幅度几乎成比例变化。在正常林格氏溶液中，不同径向距离的细胞外动作电位也几乎根据刺激间隔成比例变化。在最短刺激间隔时它们降低，而对于刺激间隔长于7 - 10毫秒但短于40 - 100毫秒的情况，它们高于单次刺激时测量的水平。
