Hutton R S, Smith J L, Eldred E
Pflugers Arch. 1975;353(4):327-36. doi: 10.1007/BF00587029.
A study was made to see if contractions induced by reflex action were followed by an elevation in muscle afferent activity comparable to the post-contraction sensory discharge (PCSD) that occurs after stimulation of the ventral roots. In lightly anesthetized cats, extension reflexes of the triceps surae muscle in the otherwise denervated leg were induced by contralateral stimulation of the popliteal nerve or footpad. The reflex response was followed by an elevated afferent discharge, which disappeared after a brief stretch, as is characteristic also of the PCSD. Crossed-extension responses in fusimotor activity unaccompanied by contraction of the gross muscle were also succeeded by an elevation in sensory discharge and an increased sensitivity to a vibratory stimulus applied to the tendon. Pinna reflexes had a similar effect. In the presence of the elevated discharge, alpha-motoneurons demonstrated increased sensitivity to vibration stimuli. It is suggested that the increase in spindle sensitivity may help stabilize the muscle against minor pertubations in length, at least when background fusimotor activity is relatively quiet.
开展了一项研究，以观察反射动作诱发的收缩之后，肌肉传入活动的增强是否与刺激腹根后出现的收缩后感觉放电（PCSD）相当。在轻度麻醉的猫身上，通过对腘神经或脚垫进行对侧刺激，诱发原本去神经支配的腿部腓肠肌的伸展反射。反射反应之后是传入放电增强，在短暂拉伸后该放电消失，这也是PCSD的特征。在没有大肌肉收缩伴随的肌梭运动活动中的交叉伸展反应之后，感觉放电也会增强，并且对施加于肌腱的振动刺激的敏感性增加。耳廓反射也有类似效果。在放电增强的情况下，α运动神经元对振动刺激的敏感性增加。有人提出，纺锤体敏感性的增加可能有助于使肌肉在长度受到轻微扰动时保持稳定，至少在背景肌梭运动活动相对安静时是这样。
