1. Following motor nerve stimulation there is a period of greatly enhanced quantal release, called the early release period or ERP (Barrett & Stevens, 1972b). Until now, measurements of the probability of quantal releases at different points in the ERP have come from experiments in which quantal output was greatly reduced, so that the time of release of individual quanta could be detected or so that the latency to the release of the first quantum could be measured. 2. A method has been developed to estimate the timing of quantal release during the ERP that can be used at much higher levels of quantal output. The assumption is made that each quantal release generates an end-plate current (EPC) that rises instantaneously and then decays exponentially. The peak amplitude of the quantal currents and the time constant for their decay are measured from miniature end-plate currents (MEPCs). Then a number of EPCs are averaged, and the times of release of the individual quanta during the ERP estimated by a simple mathematical method for deconvolution derived by Cohen, Van der Kloot & Attwell (1981). 3. The deconvolution method was tested using data from preparations in high-Mg2+ low-Ca2+ solution. One test was to reconstitute the averaged EPCs from the estimated times of quantal release and the quantal currents, by using Fourier convolution. The reconstructions fit well to the originals. 4. Reconstructions were also made from averaged MEPCs which do not rise instantaneously and the estimated times of quantal release.(ABSTRACT TRUNCATED AT 250 WORDS)
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机译:1.在运动神经刺激后,有一段时期内,数量释放大大增强,称为早期释放期或ERP(Barrett&Stevens,1972b)。到目前为止,ERP中不同点的定量释放概率的测量来自实验,在该实验中,定量输出被大大降低,因此可以检测单个量子的释放时间,或者使得释放该定量的等待时间。可以测量第一量子。 2.已经开发出一种方法来估算ERP中定量释放的时间,该方法可用于更高水平的定量输出。假定每个定量释放都会产生一个端板电流(EPC),该电流瞬时上升,然后呈指数下降。量化电流的峰值幅度和衰减的时间常数是从微型端板电流(MEPC)测量的。然后,对多个EPC进行平均,并通过Cohen,Van der Kloot和Attwell(1981)推导的简单反卷积数学方法估算ERP中各个量子的释放时间。 3.使用高Mg2 +低Ca2 +溶液中制剂的数据测试了去卷积方法。一种测试是通过使用傅立叶卷积从估计的定量释放时间和定量电流重构平均EPC。重建物非常适合原始物。 4.还从不是立即上升的平均MEPC和估计的定量释放时间进行了重构。(摘要以250字截短)
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