Peripheral and intraspinal feedback is required to shape and update the output of spinal networks that execute motor behavior. We report that lumbar dI2 spinal interneurons of the chick receive synaptic input from afferents and pre-motoneurons. They innervate contralateral premotor networks in the lumbar and brachial spinal cord and their ascending projections innervate the cerebellum. These findings suggest that dI2 neurons function as interneurons in local lumbar circuits and involved in lumbo-brachial coupling and that part of them deliver peripheral and intraspinal feedback to the cerebellum. Silencing of dI2 neurons leads to destabilized stepping in P8 hatchlings with occasional collapses, variable step-profiles and wide-base walking, suggesting that the dI2 neurons may contribute to stabilization of the bipedal gait.

中文翻译：

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脊髓dI2中间神经元调节双足踏步的稳定性

需要外围和脊柱内反馈来塑造和更新执行运动行为的脊柱网络的输出。我们报告说，小鸡的腰dI2脊神经中枢从传入神经元和运动神经元前突触输入。它们支配腰和臂脊髓中的对侧运动前神经网络，其上升的突起支配小脑。这些发现表明，dI2神经元在局部腰部回路中起中间神经元的作用，并参与腰肱臂耦合，并且它们的一部分将周围和脊柱内反馈传递到小脑。dI2神经元的沉默会导致P8孵化中的步伐不稳定，偶尔会崩溃，变化的步态和宽阔的步态，这表明dI2神经元可能有助于稳定双足步态。