National Institutes of Natural Sciences, Exploratory Research Center on Life and Living Systems, National Institute for Basic Biology, Okazaki, Aichi 444-8787, Japan.
National Institutes of Natural Sciences, Exploratory Research Center on Life and Living Systems, National Institute for Basic Biology, Okazaki, Aichi 444-8787, Japan; Graduate University for Advanced Studies, Okazaki, Aichi 444-8787, Japan.
Cell Rep. 2020 Mar 3;30(9):3036-3050.e4. doi: 10.1016/j.celrep.2020.02.015.
Commissural inhibitory neurons in the spinal cord of aquatic vertebrates coordinate left-right body alternation during swimming. Their developmental origin, however, has been elusive. We investigate this by comparing the anatomy and function of two commissural inhibitory neuron types, dI6dmrt3a and V0d, derived from the pd6 and p0 progenitor domains, respectively. We find that both of these commissural neuron types have monosynaptic, inhibitory connections to neuronal populations active during fictive swimming, supporting their role in providing inhibition to the contralateral side. V0d neurons tend to fire during faster and stronger movements, while dI6dmrt3a neurons tend to fire more consistently during normal fictive swimming. Ablation of dI6dmrt3a neurons leads to an impairment of left-right alternating activity through abnormal co-activation of ventral root neurons on both sides of the spinal cord. Our results suggest that dI6dmrt3a and V0d commissural inhibitory neurons synergistically provide inhibition to the opposite side across different swimming behaviors.
水栖脊椎动物脊髓中的连合性抑制神经元在游泳时协调左右身体交替。然而，它们的发育起源一直难以捉摸。我们通过比较分别来自 pd6 和 p0 祖细胞域的两种连合性抑制神经元类型 dI6dmrt3a 和 V0d 的解剖结构和功能来研究这一点。我们发现这两种连合性神经元类型都与在虚拟游泳过程中活跃的神经元群体具有单突触抑制性连接，支持它们在向对侧提供抑制作用的作用。V0d 神经元往往在更快和更强的运动中发射，而 dI6dmrt3a 神经元往往在正常的虚拟游泳中更一致地发射。dI6dmrt3a 神经元的消融会导致脊髓两侧腹根神经元异常共同激活，从而损害左右交替活动。我们的结果表明，dI6dmrt3a 和 V0d 连合性抑制神经元在不同的游泳行为中协同向对侧提供抑制。
