Crossed reflex responses to flexor nerve stimulation in mice.
Crossed reflex responses to flexor nerve stimulation in mice.
复制标题
小鼠对屈肌神经刺激的交叉反射反应。
DOI：
10.1152/jn.00385.2021
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发表时间：
2022
影响因子：
2.5
通讯作者：
Akay,Turgay
中科院分区：
文献类型：
--
作者：
Laflamme,OlivierD;Ibrahim,Marwan;Akay,Turgay
一条腿对对侧腿感觉刺激的运动反应被称为交叉反射，并在猫和人类身上进行了广泛的研究。尽管做出了这样的努力，但对交叉反射的电路层面的理解仍然缺乏。在小鼠身上，分子遗传学的进步使人们能够深入了解确保腿部在运动过程中协调运动的“连合脊髓回路”。尽管连合脊髓环路和交叉反射环路之间有一些共同特征，但它们的重叠程度仍然不清楚。在此，我们描述了电刺激主要支配踝屈肌和后腿前外侧皮肤的腓总神经所引起的兴奋性交叉反射反应。以低电流强度刺激腓神经，可引起对侧屈伸肌的低幅度运动反应。在较高的电流强度下，刺激相同的神经在相同的对侧肌肉中引起更强和更同步的反应。除了肌肉激活所指示的兴奋性交叉反射通路外，我们还证明了抑制性交叉反射通路的存在，当运动池在行走过程中活跃时，该通路被调节。结果与刺激伸肌本体感受器和小腿后部皮肤传入所引起的交叉反射反应进行了比较。我们预计，这些发现将对未来的研究至关重要，将这里介绍的活体实验与小鼠遗传学相结合，以在活体网络水平上了解交叉反射路径。新与新对交叉反射机制的洞察对于理解保持稳定运动的协调腿部运动至关重要。小鼠遗传学的进步允许选择性地操纵脊髓中间神经元，并为理解交叉反射提供了机会。然而，对小鼠的交叉反射的描述很少。在这里，我们描述了由刺激腓总神经引起的小鼠的交叉反射反应，这是在细胞水平上研究交叉反射的起点。
Motor responses in one leg to sensory stimulation of the contralateral leg have been named “crossed reflexes” and are extensively investigated in cats and humans. Despite this effort, a circuit-level understanding of the crossed reflexes has remained missing. In mice, advances in molecular genetics enabled insights into the “commissural spinal circuitry” that ensures coordinated leg movements during locomotion. Despite some common features between the commissural spinal circuitry and the circuit for the crossed reflexes, the degree to which they overlap has remained obscure. Here, we describe excitatory crossed reflex responses elicited by electrically stimulating the common peroneal nerve that mainly innervates ankle flexor muscles and the skin on anterolateral aspect of the hind leg. Stimulation of the peroneal nerve with low current intensity evoked low-amplitude motor responses in the contralateral flexor and extensor muscles. At higher current strengths, stimulation of the same nerve evoked stronger and more synchronous responses in the same contralateral muscles. In addition to the excitatory crossed reflex pathway indicated by muscle activation, we demonstrate the presence of an inhibitory crossed reflex pathway, which was modulated when the motor pools were active during walking. The results are compared with the crossed reflex responses initiated by stimulating proprioceptors from extensor muscles and cutaneous afferents from the posterior part of the leg. We anticipate that these findings will be essential for future research combining the in vivo experiments presented here with mouse genetics to understand crossed reflex pathways at the network level in vivo.NEW & NOTEWORTHYInsights into the mechanisms of crossed reflexes are essential for understanding coordinated leg movements that maintain stable locomotion. Advances in mouse genetics allow for the selective manipulation of spinal interneurons and provide opportunities to understand crossed reflexes. Crossed reflexes in mice, however, are poorly described. Here, we describe crossed reflex responses in mice initiated by stimulation of the common peroneal nerve, which serves as a starting point for investigating crossed reflexes at the cellular level.