Zhu Qinghua, Han Fang, Yu Ying, Wang Fengjie, Wang Qingyun, Shakeel Awais
College of Information Science and Technology, Donghua University, Shanghai, 201620, China.
College of Information Science and Technology, Donghua University, Shanghai, 201620, China.
Neural Netw. 2024 Oct;178:106422. doi: 10.1016/j.neunet.2024.106422. Epub 2024 Jun 3.
Locomotion and scratching are basic motor functions which are critically important for animal survival. Although the spinal circuits governing forward locomotion have been extensively investigated, the organization of spinal circuits and neural mechanisms regulating backward locomotion and scratching remain unclear. Here, we extend a model by Danner et al. to propose a spinal circuit model with asymmetrical cervical-lumbar layout to investigate these issues. In the model, the left-right alternation within the cervical and lumbar circuits is mediated by V 0 and V 0 commissural interneurons (CINs), respectively. With different control strategies, the model closely reproduces multiple experimental data of quadrupeds in different motor behaviors. Specifically, under the supraspinal drive, walk and trot are expressed in control condition, half-bound is expressed after deletion of V 0 CINs, and bound is expressed after deletion of V0 (V 0 and V 0) CINs; in addition, unilateral hindlimb scratching occurs in control condition and synchronous bilateral hindlimb scratching appears after deletion of V 0 CINs. Under the combined drive of afferent feedback and perineal stimulation, different coordination patterns between hindlimbs during BBS (backward-biped-spinal) locomotion are generated. The results suggest that (1) the cervical and lumbar circuits in the spinal network are asymmetrically recruited during particular rhythmic limb movements. (2) Multiple motor behaviors share a single spinal network under the reconfiguration of the spinal network by supraspinal inputs or somatosensory feedback. Our model provides new insights into the organization of motor circuits and neural control of rhythmic limb movements.
运动和抓挠是对动物生存至关重要的基本运动功能。尽管对控制向前运动的脊髓回路已进行了广泛研究，但调节向后运动和抓挠的脊髓回路组织及神经机制仍不清楚。在此，我们扩展了丹纳等人的一个模型，提出一个具有不对称颈腰布局的脊髓回路模型来研究这些问题。在该模型中，颈段和腰段回路内的左右交替分别由V0和V0连合中间神经元（CINs）介导。通过不同的控制策略，该模型能紧密再现四足动物在不同运动行为中的多个实验数据。具体而言，在脊髓上驱动下，控制条件下表现出行走和小跑，删除V0 CINs后表现出半束缚态，删除V0（V0和V0）CINs后表现出束缚态；此外，控制条件下单侧后肢抓挠出现，删除V0 CINs后出现同步双侧后肢抓挠。在传入反馈和会阴刺激的联合驱动下，在BBS（向后双足脊髓）运动过程中后肢之间产生了不同的协调模式。结果表明：（1）在特定的节律性肢体运动过程中，脊髓网络中的颈段和腰段回路被不对称地募集。（2）在脊髓上输入或体感反馈对脊髓网络进行重构的情况下，多种运动行为共享单个脊髓网络。我们的模型为运动回路的组织和节律性肢体运动的神经控制提供了新的见解。
