Decoding the rules of recruitment of excitatory interneurons in the adult zebrafish locomotor network
Decoding the rules of recruitment of excitatory interneurons in the adult zebrafish locomotor network
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DOI：
10.1073/pnas.1216256110
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发表时间：
2012-12-26
影响因子：
11.1
通讯作者：
El Manira, Abdeljabbar
中科院分区：
文献类型：
--
作者：
Ausborn, Jessica;Mahmood, Riyadh;El Manira, Abdeljabbar
脊髓中的神经网络将来自大脑的信号转换为协调的运动运动。运动速度的最佳调整需要这些网络内潜在兴奋的中间神经元精确的招募顺序。然而，兴奋性中间神经元募集阈值的编码机制仍不清楚。在这里，我们使用幼年/成年斑马鱼制剂显示，随着游泳频率的增加，兴奋性V2a中间神经元被逐渐招募。V2a中间神经元的起搏顺序不受地形或输入阻抗的影响。相反，它是由输入电阻来衡量兴奋性突触电流的影响而决定的。我们还表明，运动网络是由多个微电路组成的，这些微电路包括V2a中间神经元和运动神经元的子集，这些子集随着游泳速度的增加而以连续的方式招募。因此，我们的结果提供了对决定脊髓微回路招募的组织和机制的洞察，以确保运动的最佳执行。
Neural networks in the spinal cord transform signals from the brain into coordinated locomotor movements. An optimal adjustment of the speed of locomotion entails a precise order of recruitment of interneurons underlying excitation within these networks. However, the mechanisms encoding the recruitment threshold of excitatory interneurons have remained unclear. Here we show, using a juvenile/adult zebrafish preparation, that excitatory V2a interneurons are incrementally recruited with increased swimming frequency. The order of recruitment is not imprinted by the topography or the input resistance of the V2a interneurons. Rather, it is determined by scaling the effect of excitatory synaptic currents by the input resistance. We also show that the locomotor networks are composed of multiple microcircuits encompassing subsets of V2a interneurons and motoneurons that are recruited in a continuum with increased swimming speeds. Thus, our results provide insights into the organization and mechanisms determining the recruitment of spinal microcircuits to ensure optimal execution of locomotor movements.