Akahoshi Taichi, Utsumi Madoka K, Oonuma Kouhei, Murakami Makoto, Horie Takeo, Kusakabe Takehiro G, Oka Kotaro, Hotta Kohji
Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Kohoku, Yokohama 223-8522, Japan.
Institute for Integrative Neurobiology and Department of Biology, Konan University, Kobe 658-8501, Japan.
Sci Adv. 2021 Dec 10;7(50):eabl6053. doi: 10.1126/sciadv.abl6053.
Recent work in tunicate supports the similarity between the motor circuits of vertebrates and basal deuterostome lineages. To understand how the rhythmic activity in motor circuits is acquired during development of protochordate , we investigated the coordination of the motor response by identifying a single pair of oscillatory motor neurons (MN2/A10.64). The MN2 neurons had Ca oscillation with an ~80-s interval that was cell autonomous even in a dissociated single cell. The Ca oscillation of MN2 coincided with the early tail flick (ETF). The spikes of the membrane potential in MN2 gradually correlated with the rhythm of ipsilateral muscle contractions in ETFs. The optogenetic experiments indicated that MN2 is a necessary and sufficient component of ETFs. These results indicate that MN2 is indispensable for the early spontaneous rhythmic motor behavior of . Our findings shed light on the understanding of development and evolution of chordate rhythmical locomotion.
最近在被囊动物中的研究支持了脊椎动物和基础后口动物谱系运动回路之间的相似性。为了了解原索动物发育过程中运动回路的节律性活动是如何获得的，我们通过识别一对振荡运动神经元（MN2/A10.64）来研究运动反应的协调性。MN2神经元具有约80秒间隔的钙振荡，即使在解离的单细胞中也是细胞自主的。MN2的钙振荡与早期甩尾（ETF）同步。MN2中膜电位的尖峰逐渐与ETF中同侧肌肉收缩的节律相关。光遗传学实验表明MN2是ETF的必要且充分组成部分。这些结果表明MN2对于早期自发节律性运动行为是不可或缺的。我们的发现为理解脊索动物节律性运动的发育和进化提供了线索。
