Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA 19129, USA.
Int J Mol Sci. 2022 May 16;23(10):5541. doi: 10.3390/ijms23105541.
We describe and analyze a computational model of neural circuits in the mammalian spinal cord responsible for generating and shaping locomotor-like oscillations. The model represents interacting populations of spinal neurons, including the neurons that were genetically identified and characterized in a series of previous experimental studies. Here, we specifically focus on the ipsilaterally projecting V1 interneurons, their possible role in the spinal locomotor circuitry, and their involvement in the generation of locomotor oscillations. The proposed connections of these neurons and their involvement in different neuronal pathways in the spinal cord allow the model to reproduce the results of optogenetic manipulations of these neurons under different experimental conditions. We suggest the existence of two distinct populations of V1 interneurons mediating different ipsilateral and contralateral interactions within the spinal cord. The model proposes explanations for multiple experimental data concerning the effects of optogenetic silencing and activation of V1 interneurons on the frequency of locomotor oscillations in the intact cord and hemicord under different experimental conditions. Our simulations provide an important insight into the organization of locomotor circuitry in the mammalian spinal cord.
我们描述和分析了一个负责产生和塑造类似运动的振荡的哺乳动物脊髓神经回路的计算模型。该模型代表了相互作用的脊髓神经元群体，包括在一系列先前的实验研究中被基因鉴定和表征的神经元。在这里，我们特别关注向同侧投射的 V1 中间神经元，它们在脊髓运动电路中的可能作用，以及它们在运动振荡产生中的参与。这些神经元的提出的连接及其在脊髓中不同神经元通路中的参与，使该模型能够再现在不同实验条件下对这些神经元进行光遗传学操作的结果。我们提出了两种不同的 V1 中间神经元群体的存在，它们在脊髓内介导不同的同侧和对侧相互作用。该模型对多个实验数据提出了解释，这些数据涉及在不同实验条件下光遗传沉默和激活 V1 中间神经元对完整脊髓和半脊髓中运动振荡频率的影响。我们的模拟为哺乳动物脊髓运动电路的组织提供了重要的见解。
