Rymer W Z, Houk J C, Crago P E
Exp Brain Res. 1979 Sep;37(1):93-113. doi: 10.1007/BF01474257.
The mechanisms of the clasp-knife reflex were studied in the soleus muscle of an animal model, the decerebrate cat with a dorsal hemisection of the lower thoracic cord. The reflex is shown to be autogenetic, and to depend on muscle length in keeping with previous suggestions. However, the magnitude of the inhibition increases with increasing initial force, and the inhibition is mimicked by gentle manipulation of the muscle and tendon surface. Concurrent muscle afferent recordings showed that the electromyogram (emg) reduction was not a result of a decline in Ia afferent input and was not well related to secondary or tendon organ afferent discharge. It is now known that many group III and some group IV muscle afferents are also activated by muscle stretch and contraction, and we here report limited stretch sensitivity in four non-spindle group II afferents. Since these fiber groups each include afferents that produce inhibition of extensor motoneurons, it is proposed that the clasp-knife reflex may result from the activation of these slowly conducting afferent fibers.
在动物模型（下胸段脊髓背侧半横断的去大脑猫）的比目鱼肌中研究了折刀样反射的机制。结果表明，该反射是自生的，并且如先前研究所提示的那样，取决于肌肉长度。然而，抑制的程度随着初始力的增加而增加，并且通过轻柔地操作肌肉和肌腱表面可模拟出这种抑制。同时进行的肌肉传入神经记录显示，肌电图（emg）的降低并非Ia传入神经输入减少的结果，并且与次级或腱器官传入神经放电没有很好的相关性。现在已知许多III类和一些IV类肌肉传入神经也会被肌肉拉伸和收缩激活，并且我们在此报告了四条非梭形II类传入神经有限的拉伸敏感性。由于这些纤维群各自都包含能抑制伸肌运动神经元的传入神经，因此有人提出折刀样反射可能是由这些传导速度较慢的传入纤维的激活所导致的。
