Voltage clamping of unparalysed cut rat diaphragm for study of transmitter release.
Voltage clamping of unparalysed cut rat diaphragm for study of transmitter release.
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对未瘫痪的切割大鼠隔膜进行电压钳位，用于研究发射器释放。
DOI：
10.1113/jphysiol.1979.sp012784
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发表时间：
1979
期刊：
影响因子：
--
通讯作者：
M. Glavinović
中科院分区：
文献类型：
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作者：
M. Glavinović
1.切断后，大鼠膈肌的膜电位、输入电阻和空间常数均下降，刺激膈神经时无收缩现象。虽然切割制剂中端板电流的反转电位看起来正常，但微小端板电流的大小(m.e.p.c.s.)略有下降。2.外源钾浓度从2.5 mM增加到10.0 mM时，释放量的统计参数(m、n和p)变化不大(小于5%)。ME.P.C.的大小。也几乎没有变化。3.温度从37摄氏度下降到15摄氏度，导致m、n和p的下降；然而，在25摄氏度时，这些值比37摄氏度时小不到25%。4.与以往关于蛙神经肌肉接头的报道一样，电压钳制引起的切断和未切断的大鼠横隔肌膜电位的变化仅在外钾浓度升高的介质中影响肌电活动的频率。在切割和未切割的制剂中，肌电活动频率与肌膜电位的依赖关系非常相似。肌膜电位的变化不影响正常介质中切割剂的诱发释放。
1. As a result of the cutting procedure there is a decrease in the membrane potential, input resistance, and space constant of the rat diaphragm, and there is no contraction when the phrenic nerve is stimulated. While the reversal potential of end‐plate currents in cut preparations appears normal, the size of miniature end‐plate currents (m.e.p.c.s.) is slightly decreased. 2. An increase in the external concentration of potassium from 2.5 to 10.0 mM results only in a minor change (less than 5%) in statistical parameters of transmitter release (m, n and p). The size of m.e.p.c. is also almost unchanged. 3. A decrease in temperature from 37 degrees to 15 degrees C resulted in a decrease of m, n and p; however, the values are less than 25% smaller at 25 degrees C than at 37 degrees C. The size of m.e.p.c.s is very insensitive to changes in temperature. 4. As previously reported for the frog neuromuscular junction, changes in muscle membrane potential of cut and uncut rat diaphragm due to voltage clamping affect the frequency of m.e.p.c.s only in medium with raised external K concentration. The dependence of frequency of m.e.p.c.s on muscle membrane potential is remarkably similar in cut and uncut preparations. Evoked release in cut preparation in normal medium is not affected by the change in muscle membrane potential.