Glavinović M I
Department of Anaesthesia Research, McGill University, Montreal, P.Q., Canada.
Neuroscience. 1988 Apr;25(1):283-9. doi: 10.1016/0306-4522(88)90026-7.
The decrease in amplitude of endplate potentials that occurs with high frequency nerve stimulation at the rat phrenic-diaphragm preparation is greater after blockade of choline uptake by hemicholinium-3. The effect is mainly presynaptic and occurs after presumably only a small fraction of the total number of releasable quanta has been discharged. Moreover, when the phrenic nerve is stimulated with a rapid sequence of short tetanic trains, the decrease of the amplitude of both the "first" and the "last" endplate potential of each train which is usually monoexponential becomes not only greater but also biphasic. The effect on the "first" endplate potentials is particularly large. This can be interpreted as further evidence that newly synthesized acetylcholine preferentially replenishes the immediately available store of quanta released by nerve stimulation.
在大鼠膈神经 - 膈肌标本上，用高频神经刺激时，终板电位幅度的降低在被3 - 碘季铵酚阻断胆碱摄取后更大。这种效应主要是突触前的，并且大概是在仅一小部分可释放量子总数被释放之后发生的。此外，当用短强直串的快速序列刺激膈神经时，通常呈单指数形式的每个串的“第一个”和“最后一个”终板电位幅度的降低不仅变得更大，而且变为双相。对“第一个”终板电位的影响尤为显著。这可以解释为进一步的证据，即新合成的乙酰胆碱优先补充由神经刺激释放的量子的即时可用储备。
