Matsumura M, Hino N
Nihon Seirigaku Zasshi. 1977 Feb;39(2):31-5.
It is known that the properties of the excitation-contraction coupling of crayfish skeletal muscle are different in some respects from those of frog muscle. In the present study, activation of contraction of the crayfish muscle induced by short depolarizing pulses was investigated and it was compared with the results of frog muscle obtained by Adrian, Chandler and Hodgkin (1969). Two glass microelectrodes were inserted into the thoracal muscle of the crayfish. The muscle was stimulated by the voltage-clamped pulses of different durations and the resulting contractions were observed under the binocular microscope with the magnification of 60 X at 20 approximately 23 degrees C. The rheobasic membrane potential was -55mV. The mechanical threshold potential was -42 mV for 10 msec, -15 mV for 2.5 msec, +18 mV for 1 msec and around +90 mV for 0.5 msec pulses. For short pulses where the threshold potential was more positive than -20 mV, the area of the depolarization above -30 mV was 51 mV-msec. Subthreshold pulses produced contraction if applied repetitively. The effect of a just suprathreshold short pulse on the activation of contraction was cancelled by the hyperpolarizing pulse.
已知小龙虾骨骼肌的兴奋-收缩偶联特性在某些方面与青蛙肌肉不同。在本研究中，研究了短去极化脉冲诱导的小龙虾肌肉收缩激活，并将其与阿德里安、钱德勒和霍奇金（1969年）在青蛙肌肉上获得的结果进行了比较。将两根玻璃微电极插入小龙虾的胸肌。用不同持续时间的电压钳制脉冲刺激肌肉，并在双目显微镜下观察由此产生的收缩，显微镜放大倍数为60倍，温度约为20至23摄氏度。基强度膜电位为-55mV。对于10毫秒的脉冲，机械阈电位为-42mV；对于2.5毫秒的脉冲，为-15mV；对于1毫秒的脉冲，为+18mV；对于0.5毫秒的脉冲，约为+90mV。对于阈电位比-20mV更正的短脉冲，-30mV以上的去极化面积为51mV-毫秒。阈下脉冲重复施加时会产生收缩。刚好阈上的短脉冲对收缩激活的作用会被超极化脉冲抵消。
