Activity of the left and right central pattern generators (CPGs) is efficiently coordinated during locomotion. To achieve this coordination, the interplay between the CPG controlling one leg and that controlling another must be present. Previous findings in aquatic vertebrates and mammalians suggest that the alternate activation of the left and right CPGs is mediated by the commissural interneurons crossing the midline of the spinal cord. Especially, V0 commissural interneurons mediate crossed inhibition during alternative activity of the left and right CPGs. Even in humans, phase-dependent modulation of the crossed afferent inhibition during gait has been reported. Based on those previous findings, crossed inhibition of the CPG in one leg side caused by the activation of the contralateral CPG is possible mechanism underlying the coordination of the anti-phase rhythmic movement of the legs. It has been hypothesized that the activity of the flexor half center in the CPG inhibits the contralateral flexor half center, but crossed inhibition of the extensor half center is not present because of existence of the double limb support during gait. Nevertheless, previous findings on the phase-dependent crossed inhibition during anti-phase bilateral movement of the legs are not in line with this hypothesis. For example, extensor activity caused crossed inhibition of the flexor half center during bilateral cycling of the legs. In another study, the ankle extensor was inhibited at the period switching from extension to flexion during anti-phase rhythmic movement of the ankles.

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相依赖的交叉抑制介导反相的双节律性运动的协调：迷你回顾

左右中央模式生成器（CPG）的活动在移动过程中得到有效协调。为了实现这种协调，必须存在控制一条腿的CPG与控制另一条腿的CPG之间的相互作用。在水生脊椎动物和哺乳动物中的先前发现表明，左CPG和右CPG的交替激活是由穿过脊髓中线的连合神经元介导的。特别是，V0连合中间神经元在左右CPG的交替活动期间介导交叉抑制。即使在人类中，也已经报道了步态期间交叉传入抑制的相位依赖性调节。根据先前的发现，对侧CPG的激活引起的单腿CPG的交叉抑制可能是腿的反相节律性运动协调的潜在机制。已经假设CPG中屈肌半中心的活动抑制了对侧屈肌半中心，但是由于步态中存在双肢支撑，因此不存在对伸肌半中心的交叉抑制。然而，先前关于腿反相双侧运动过程中相依赖性交叉抑制的发现与该假设不一致。例如，在腿的双侧骑行过程中，伸肌活动引起了屈半中心的交叉抑制。在另一项研究中