A KINEMATIC AND ELECTROMYOGRAPHIC STUDY OF CUTANEOUS REFLEXES EVOKED FROM THE FORELIMB OF UNRESTRAINED WALKING CATS
A KINEMATIC AND ELECTROMYOGRAPHIC STUDY OF CUTANEOUS REFLEXES EVOKED FROM THE FORELIMB OF UNRESTRAINED WALKING CATS
复制标题
DOI：
10.1152/jn.1987.57.4.1160
复制
发表时间：
1987-04-01
影响因子：
2.5
通讯作者：
ROSSIGNOL, S
中科院分区：
文献类型：
--
作者：
DREW, T;ROSSIGNOL, S
用运动学和肌电(EMG)方法分析了猫在摆动阶段机械阻塞前肢或在摆动和站立时电刺激低阈值皮肤传入所引起的反应。用一根硬金属棒机械地阻挡前肢，会引起复杂的反应，使猫能够顺利通过障碍物，而不会过度扰乱整体运动节奏。最初的运动是肩部屈曲，肘关节锁定，手腕背屈，导致肢体退出障碍。然后是肩部的伸展、肘部的屈曲和手腕的腹屈，这些动作一起使肢体向前移动，越过障碍物。相关和复杂的短潜伏期和长潜伏期肌电反应模式被证明与运动的不同方面有关。在肩部，屈肌有很强的激活；这些反应持续时间较长(大于或等于100ms)，通常持续整个肩屈曲期。在肘部，短潜伏期(9~13ms)同时激活屈肌和伸肌。在屈肌中，紧随其后的是活动的停止，随后是活动的增强和延长。手腕和手指的背屈肌在短潜伏期(10-12ms)被激活，并在这些关节的背屈期间保持活跃。在与金属棒接触的皮肤区域注射局部麻醉剂可减少或消除所有反射反应，这表明皮肤反射通路的完整性对这些反应的阐述是必不可少的。电刺激支配前肢远端的皮神经(浅的放射神经)，导致与机械刺激所获得的反应定性相似，尽管较弱。终末实验证实，这些反应是由低阈值皮肤传入所介导的。电刺激也可引起肘伸肌短潜伏期兴奋性反应(10-12ms)。一般情况下，屈肌、伸肌和双功能肌在摆动阶段获得的反射效应最大。站立时，刺激对兴奋屈肌和伸肌通常无效，引起短暂的潜伏期抑制，随后经常是活动增加。
A kinematic and electromyographic (EMG) analysis was undertaken of the responses evoked in the forelimb of the cat by either mechanical obstruction of the forelimb during the swing phase of locomotion or by electrical stimulation of low-threshold cutaneous afferents during both swing and stance. Mechanical obstruction of the forelimb with a stiff metal rod evoked a complex response that allowed the cat to smoothly negotiate the obstacle without undue disruption of the overall locomotor rhythm. The initial movements were a flexion of the shoulder, together with a locking of the elbow joint, and a dorsiflexion of the wrist, which caused the limb to withdraw from the obstacle. They were followed by an extension of the shoulder, a flexion of the elbow, and a ventroflexion of the wrist, which together brought the limb forward and above the obstacle. The associated and complex pattern of short- and long-latency EMG responses was shown to be related to different aspects of the movement. At the shoulder there was a strong activation of flexor muscles; these responses were of long duration (greater than or equal to 100 ms) and generally lasted throughout the period of shoulder flexion. At the elbow, both flexor and extensor muscles were activated at short latency (9-13 ms). In flexors, this was followed by a cessation and subsequently an augmentation and prolongation of their activity. Dorsiflexors of both the wrist and digits were activated at short latency (10-12 ms) and remained active throughout the period of dorsiflexion of these joints. An injection of a local anesthetic into the area of skin contacted by the metal rod reduced or abolished all of the reflex responses, which suggests that the integrity of cutaneous reflex pathways is essential for the elaboration of these responses. Electrical stimulation of a cutaneous nerve innervating the distal forelimb (the superficial radial nerve) resulted in qualitatively similar, although weaker, responses to those obtained with the mechanical stimulation. Terminal experiments confirmed that these responses were mediated by low-threshold cutaneous afferents. Electrical stimulation also evoked short-latency excitatory responses (10-12 ms) in extensor muscles of the elbow. Generally, the largest reflex effects were obtained during the period of swing for flexor, extensor, and bifunctional muscles. During stance the stimulus was normally ineffective in exciting flexor muscles and in extensors evoked a short-latency inhibition, which was frequently followed by an increase in activity.(ABSTRACT TRUNCATED AT 400 WORDS)