Howard Hughes Medical Institute, Kavli Institute for Brain Science, Departments of Neuroscience and Biochemistry and Molecular Biophysics, Columbia University, New York, New York, USA.
Nat Neurosci. 2010 Oct;13(10):1233-9. doi: 10.1038/nn.2637. Epub 2010 Sep 12.
Proprioceptive sensory signals inform the CNS of the consequences of motor acts, but effective motor planning involves internal neural systems capable of anticipating actual sensory feedback. Just where and how predictive systems exert their influence remains poorly understood. We explored the possibility that spinocerebellar neurons that convey proprioceptive sensory information also integrate information from cortical command systems. Analysis of the circuitry and physiology of identified dorsal spinocerebellar tract neurons in mouse spinal cord revealed distinct populations of Clarke's column neurons that received direct excitatory and/or indirect inhibitory inputs from descending corticospinal axons. The convergence of these descending inhibitory and excitatory inputs to Clarke's column neurons established local spinal circuits with the capacity to mark or modulate incoming proprioceptive input. Together, our genetic, anatomical and physiological results indicate that Clarke's column spinocerebellar neurons nucleate local spinal corollary circuits that are relevant to motor planning and evaluation.
本体感觉感觉信号将运动行为的后果告知中枢神经系统，但有效的运动规划涉及能够预测实际感觉反馈的内部神经系统。预测系统在哪里以及如何发挥其影响仍知之甚少。我们探讨了这样一种可能性，即传递本体感觉感觉信息的脊髓小脑后束神经元也整合来自皮质命令系统的信息。对小鼠脊髓中已鉴定的背侧脊髓小脑后束神经元的电路和生理学分析表明，存在明显的 Clarke 柱神经元群体，它们接收来自下行皮质脊髓轴突的直接兴奋性和/或间接抑制性输入。这些下行抑制性和兴奋性输入会聚到 Clarke 柱神经元，建立了具有标记或调节传入本体感觉输入能力的局部脊髓回路。总之，我们的遗传、解剖和生理学结果表明，Clarke 柱脊髓小脑后束神经元形成与运动规划和评估相关的局部脊髓伴随回路。
