Shefchyk S, McCrea D, Kriellaars D, Fortier P, Jordan L
Department of Medicine, University of Manitoba, Winnipeg, Canada.
Exp Brain Res. 1990;80(2):290-5. doi: 10.1007/BF00228156.
Extracellular recordings from interneurons located in the L4 spinal segment were made during fictive locomotion produced by electrical stimulation of the mesencephalic locomotor region (MLR) in the paralysed decerebrate cat. Only interneurons within the L4 segment which received group II input from quadriceps, sartorius or the pretibial flexor muscle afferents and which had axonal projections to motor nuclei in L7 were selected for analysis. During the fictive step cycle two thirds of these interneurons fired action potentials during the time of activity in the ipsilateral hindlimb flexor neurograms. These cells were also less responsive to peripheral input during the extension phase of the fictive locomotion cycle. The remaining one third of the interneurons examined were not rhythmically active during locomotion. The possible contributions of the midlumbar interneurons to motoneuron activity during locomotion are discussed.
在瘫痪的去大脑猫中，通过电刺激中脑运动区（MLR）产生虚拟运动时，对位于L4脊髓节段的中间神经元进行了细胞外记录。仅选择L4节段内那些接受来自股四头肌、缝匠肌或胫骨前屈肌传入纤维的II类输入且轴突投射至L7运动核的中间神经元进行分析。在虚拟步周期中，这些中间神经元中有三分之二在同侧后肢屈肌神经图活动期间发放动作电位。在虚拟运动周期的伸展期，这些细胞对周围输入的反应也较弱。其余三分之一被检查的中间神经元在运动期间没有节律性活动。讨论了腰中部中间神经元在运动期间对运动神经元活动的可能贡献。
