NON-LINEAR SUMMATION OF ENDPLATE POTENTIALS IN THE FROG AND MOUSE
NON-LINEAR SUMMATION OF ENDPLATE POTENTIALS IN THE FROG AND MOUSE
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DOI：
10.1113/jphysiol.1981.sp013586
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发表时间：
1981-01-01
影响因子：
5.5
通讯作者：
MARTIN, AR
中科院分区：
文献类型：
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作者：
MCLACHLAN, EM;MARTIN, AR
终板电位(E.P.P.)和端板电流(e.p.c.)在不同的弯曲化程度下，从蛙和小鼠的肌肉纤维细胞内记录，以确定电位变化与大范围内的突触电导变化之间的关系。波幅。在青蛙肌肉纤维中，EP.P.-E.P.C.Ep与Ep呈线性关系。幅度高达约10 mV。在10 mV以上，EP.P.增加的速度。随着E.P.C.的增加，幅度逐渐变小。波幅增大。马丁提出的修正这种非线性的方程式始终过度修正了EP.P。波幅。当ACh[乙酰胆碱]离子导入终板产生长时间的突触电位和电流时，电压-电流关系比神经诱发反应表现出更大的非线性。对突触电位波幅的校正结果是线性关系。环境保护与环境保护的关系。和e.p.c。小鼠肌肉的振幅表现出比青蛙肌肉更大的非线性，由该方程进行的过度校正相应地更小。计算了各种膜模型的理论电压-电流关系，并与生理关系进行了比较。小鼠肌肉的关系与无限长电缆上的点突触接触有关；青蛙肌肉的关系符合一个简单的阻容模型，没有电缆从突触区域延伸。讨论了非线性求和的几个校正因子。
Endplate potentials (e.p.p.) and endplate currents (e.p.c.) were recorded intracellularly from muscle fibers of frog and mouse at various levels of curarization to determine the relation between the potential change and the underlying synaptic conductance change over a wide range of e.p.p. amplitudes. In frog muscle fibers the e.p.p.-e.p.c. relation was linear for e.p.p. amplitudes up to about 10 mV. Beyond 10 mV the rate of increase of e.p.p. amplitude became progressively smaller as the e.p.c. amplitude increased. The equation proposed by Martin to correct for this non-linearity consistently over-corrected the e.p.p. amplitudes. When synaptic potentials and currents of long duration were produced by ionophoresis of ACh [acetylcholine] onto the endplate, the voltage-current relation showed greater non-linearity than with nerve-evoked responses. Correction of the synaptic potential amplitudes resulted in a linear relation. The relation between e.p.p. and e.p.c. amplitudes in mouse muscle showed a greater non-linearity than in frog muscle and over-correction by the equation was correspondingly smaller. Theoretical voltage-current relations were calculated for various membrane models and compared with the physiological relations. Mouse muscle relations correlated with a point synaptic contact on an infinite cable; those from frog muscle were consistent with a simple resistive-capacitative model with no cable extending from the synaptic region. Several correction factors for non-linear summation are discussed.