Lin T S, Cheng T J
Department of Neurology, National Cheng-Kung University Hospital, Tainan, Taiwan.
Muscle Nerve. 1998 Apr;21(4):482-9. doi: 10.1002/(sici)1097-4598(199804)21:4<482::aid-mus6>3.0.co;2-5.
We constructed an animal model of stimulated single-fiber electromyography (SFEMG) by testing Wistar rats under anesthesia. Stimuli of 1 Hz were applied to the sciatic nerve through an insulated monopolar needle electrode. Single-fiber action potentials were acquired from the gastrocnemius muscle. Jitter was assessed by the mean consecutive difference (MCD). Eighty-seven fibers were obtained from 12 rats. Their MCDs ranged from 2 to 72 micros (17.7+/-13.4). Seven of these values were less than or equal to 5 micros, and three exceeded 50 micros. Neuromuscular blocking agents injected into some of the rats induced considerable increases in jitter and blocking. A rat with one fiber with an MCD less than 5 micros also received an injection of curare. The jitter showed the same pattern of increment, evidence that the small jitter was not attributable to direct muscle stimulation. These results show that SFEMG can be used on rats. In addition, jitter reflects the changes in motor end-plate function. The findings also suggest the presence of an extremely high safety factor in rat neuromuscular junctions.
我们通过在麻醉状态下对Wistar大鼠进行测试，构建了一个单纤维肌电图（SFEMG）刺激动物模型。通过绝缘单极针电极以1赫兹的频率刺激坐骨神经。从腓肠肌获取单纤维动作电位。通过平均连续差值（MCD）评估抖动。从12只大鼠身上获取了87根纤维。它们的MCD范围为2至72微秒（17.7±13.4）。其中7个值小于或等于5微秒，3个超过50微秒。向部分大鼠注射神经肌肉阻滞剂会导致抖动和阻滞显著增加。一只拥有一根MCD小于5微秒纤维的大鼠也接受了箭毒注射。抖动呈现出相同的增量模式，这证明小抖动并非由直接肌肉刺激引起。这些结果表明SFEMG可用于大鼠。此外，抖动反映了运动终板功能的变化。研究结果还表明大鼠神经肌肉接头存在极高的安全系数。
