Krutetskaia Z I, Lonskiĭ A V, Mozhaeva G N, Naumov A P
Tsitologiia. 1978 Nov;20(11):1269-77.
Asymmetrical displacement currents in the Ranvier node membrane were recorded in the normal Ringer and under the action of a neurotoxin from the scorpion Buthus eupeus venom and of the alcaloid aconitine. In the total displacement current (DC) at the beginning of the pulse (Ion), two-exponentially decaying components were extracted: a rapid component with the maximum time constant of decay about 70 microns, and a slower one with the time constant of decay--300 microns. At high negative levels of conditioning prepulse (Vc) (-130 divided by -145 mV), the maximum value of the charge transferred by the fast and slow components was estimated to be 2.6 x 10(-14) and 4.8 x 10(-14) C, respectively. The slow component of Ion decreased with lowering Vc and was inhibited by the scorpion neurotoxin and aconitine. The fast phase of Ion remained unchanged with decreasing Vc from -145 to -100 mV and toxin-treated axons. Aconitine evoked a shift in the curve relating the change displaced by the fast component to the membrane potential in the direction of hyperpolarization by 40--50 mV. The results obtained suggest that the fast and the slow components of DC are associated with the initial potential-dependent stages of the processes of channel activation and inactivation, respectively.
在正常任氏液中以及在来自蝎子东亚钳蝎毒液的神经毒素和生物碱乌头碱的作用下，记录了郎飞结膜中的不对称位移电流。在脉冲开始时的总位移电流（DC）（Ion）中，提取出两个呈指数衰减的成分：一个快速成分，其最大衰减时间常数约为70微秒，另一个较慢成分，其衰减时间常数为300微秒。在高负水平的条件预脉冲（Vc）（-130至-145 mV）下，快速和慢速成分转移的电荷最大值估计分别为2.6×10⁻¹⁴和4.8×10⁻¹⁴库仑。Ion的慢速成分随着Vc的降低而减少，并被蝎子神经毒素和乌头碱抑制。当Vc从-145 mV降至-100 mV以及在毒素处理的轴突中，Ion的快速相保持不变。乌头碱使快速成分所产生的变化与膜电位的关系曲线向超极化方向移动了40 - 50 mV。所获得的结果表明，DC的快速和慢速成分分别与通道激活和失活过程中最初的电位依赖性阶段相关。
