Activation of Multiply Innervated Fast and Slow Myotomal Muscle Fibres of the Teleost Myoxocephalus Scorpius
Activation of Multiply Innervated Fast and Slow Myotomal Muscle Fibres of the Teleost Myoxocephalus Scorpius
复制标题
硬骨鱼天蝎座多神经支配快、慢肌节肌纤维的激活
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
I. Johnston
中科院分区：
文献类型：
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作者：
J. Altringham;I. Johnston
使用来自杜父鱼的神经肌肉制剂来研究快肌纤维和慢肌纤维对脊神经刺激的膜反应。快纤维（−81.9mV）和慢纤维（−80.8mV）的静息电位没有显着差异。快速纤维以动作电位对脊神经中的阈上刺激做出反应。记录了高达+32 mV 的过冲。在慢纤维中观察到连接电位和过冲动作电位。使用分离的“活”快纤维和慢纤维束来研究肌节肌肉的抽搐/破伤风特征。两种纤维类型都会通过机械抽搐对单一刺激做出反应。快纤维在 50 Hz 左右获得融合破伤风，慢纤维在 20 Hz 左右获得融合破伤风。在慢纤维中，强直张力随着频率增加到大约 50Hz。在给出最大强直张力的频率下，快纤维的抽搐/破伤风比率为 0.70，慢纤维的抽搐/破伤风比率为 0.29。这些结果是参考硬骨鱼肌节肌肉的多神经元/多末端神经支配模式及其在运动中的作用进行讨论的。
A nerve-muscle preparation from the sculpin Myoxocephalus scorpius was used to study the membrane response of fast and slow muscle fibres to stimulation of the spinal nerves. There was no significant difference between resting potential in fast (−81.9mV) and slow fibres (−80.8mV). Fast fibres responded to a suprathreshold stimulus in the spinal nerve with an action potential. Overshoots of up to +32 mV were recorded. Both junction potentials and overshooting action potentials were observed in the slow fibres. The twitch/tetanus characteristics of myotomal muscle were investigated using isolated bundles of ‘live’ fast and slow fibres. Both fibre types responded to a single stimulus with a mechanical twitch. Fused tetani were obtained at around 50Hz in fast fibres and 20 Hz in slow fibres. In the slow fibres, tetanic tension increased with frequency up to around 50Hz. At frequencies giving maximum tetanic tension, the twitch/tetanus ratio was 0.70 for fast fibres and 0.29 for slow ones. These results are discussed with reference to the polyneuronal/multiterminal innervation pattern of the myotomal muscle in teleost fish and its role in locomotion.