Glavinović M I, Narahashi T
Department of Anaesthesia Research and Physiology, McGill University, Montreal, P.Q., Canada.
Neuroscience. 1988 Apr;25(1):271-81. doi: 10.1016/0306-4522(88)90025-5.
The phrenic nerve of an unparalysed "cut" rat diaphragm preparation was stimulated with a rapid sequence of short tetanic trains. The amplitudes of both the first and the last (25th) endplate potentials produced by short tetanic trains progressively decreased with repeated application, but the latter diminished faster. Both relative depression and relative recovery (defined as fractional decrease and fractional recovery of endplate potential amplitudes that occur during and after each short train) became more pronounced with time. Relative facilitation (defined as fractional increase of endplate potential amplitudes observed at the beginning of each train) when initially present, persisted or increased slightly with duration of stimulation. Present results suggest that the "classic" depletion model for depression ought to be modified. They can be explained if it is assumed that during stimulation the capacity of the immediately available store to contain transmitter increases, and/or that newly formed transmitter preferentially replenishes the store of quanta immediately available for release. (An interesting consequence of the former model is that the immediately available store is replenished even when the small store behind is relatively more depleted.
用短串强直刺激序列对未麻痹的“切断”大鼠膈神经膈肌标本的膈神经进行刺激。短串强直刺激产生的第一个和最后一个（第25个）终板电位的幅度随着重复刺激而逐渐降低，但后者降低得更快。相对抑制和相对恢复（定义为每次短串刺激期间和之后终板电位幅度的分数降低和分数恢复）随着时间的推移变得更加明显。最初出现的相对易化（定义为在每次刺激开始时观察到的终板电位幅度的分数增加）随着刺激持续时间的延长而持续存在或略有增加。目前的结果表明，抑郁的“经典”耗竭模型应该进行修正。如果假设在刺激期间，即时可用储存库容纳递质的能力增加，和/或新形成的递质优先补充可立即用于释放的量子储存库，那么这些结果就可以得到解释。（前一个模型的一个有趣结果是，即使后面的小储存库相对更耗竭，即时可用储存库也会得到补充。
