Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
National Institutes of Natural Sciences, Okazaki Institute for Integrative Bioscience, National Institute for Physiological Sciences, Okazaki, Aichi 444-8787, Japan.
Neuron. 2022 Apr 6;110(7):1211-1222.e4. doi: 10.1016/j.neuron.2022.01.001. Epub 2022 Jan 31.
Motor systems must continuously adapt their output to maintain a desired trajectory. While the spinal circuits underlying rhythmic locomotion are well described, little is known about how the network modulates its output strength. A major challenge has been the difficulty of recording from spinal neurons during behavior. Here, we use voltage imaging to map the membrane potential of large populations of glutamatergic neurons throughout the spinal cord of the larval zebrafish during fictive swimming in a virtual environment. We characterized a previously undescribed subpopulation of tonic-spiking ventral V3 neurons whose spike rate correlated with swimming strength and bout length. Optogenetic activation of V3 neurons led to stronger swimming and longer bouts but did not affect tail beat frequency. Genetic ablation of V3 neurons led to reduced locomotor adaptation. The power of voltage imaging allowed us to identify V3 neurons as a critical driver of locomotor adaptation in zebrafish.
运动系统必须不断调整其输出以维持期望的轨迹。虽然节律性运动的脊髓回路已经得到很好的描述，但对于网络如何调节其输出强度知之甚少。主要的挑战一直是在行为过程中从脊髓神经元进行记录的难度。在这里，我们使用电压成像来映射虚拟环境中虚构游泳期间幼鱼脊柱中谷氨酸能神经元的大群体的膜电位。我们描述了以前未描述的紧张性尖峰腹侧 V3 神经元的亚群，其尖峰率与游泳强度和回合长度相关。V3 神经元的光遗传学激活导致更强的游泳和更长的回合，但不影响尾拍频率。V3 神经元的遗传消融导致运动适应性降低。电压成像的强大功能使我们能够将 V3 神经元鉴定为斑马鱼运动适应性的关键驱动因素。
