Iles J F, Roberts R C
J Neurol Neurosurg Psychiatry. 1986 Aug;49(8):937-44. doi: 10.1136/jnnp.49.8.937.
Presynaptic inhibition of muscle spindle Ia afferents by group I afferents from the same and other muscles has been studied in the lower limbs of subjects with upper motoneuron lesions. The experiments utilised conditioning of soleus test monosynaptic reflexes during controlled voluntary contraction. The protocol was designed to isolate presynaptic inhibition from postsynaptic components. The relation between estimate of inhibition and test reflex amplitude was examined. The subjects showed less inhibition than controls at all levels of voluntary torque investigated (less than or equal 15 Nm). Two thirds had weak inhibition which did not show the decrease during muscle contraction characteristic of controls. The degree of difference from the normal situation correlated with severity of the clinical sign (weakness of voluntary ankle flexion).
在患有上运动神经元损伤的受试者下肢，研究了来自相同和其他肌肉的I类传入神经对肌梭Ia传入神经的突触前抑制。实验采用在受控的自主收缩过程中对比目鱼肌测试单突触反射进行条件刺激。该方案旨在将突触前抑制与突触后成分分离。研究了抑制估计值与测试反射幅度之间的关系。在所研究的所有自主扭矩水平（小于或等于15牛米）下，受试者的抑制作用均低于对照组。三分之二的受试者抑制作用较弱，在肌肉收缩过程中未表现出对照组特有的下降。与正常情况的差异程度与临床体征（自主踝关节背屈无力）的严重程度相关。
