Abstract：
The tail plays important roles in locomotion control in many animals. But in animals with multiple body segments, the roles of the hind body segments and corresponding innervating neurons in locomotion control are not clear. Here, using the Drosophila larva as the model animal, we investigated the roles of the posterior terminal segments in various modes of locomotion and found that they participate in all of them. In forward crawling, paralysis of the larval tail by blocking the Abdb-Gal4 labeled neurons in the posterior segments of VNC led to a slower locomotion speed but did not prevent the initiation of forward peristalsis. In backward crawling, larvae with the Abdb-Gal4 neurons inhibited were unable to generate effective displacement although waves of backward peristalsis could be initiated and persist. In head swing where the movement of the tail is not obvious, disabling the larval tail by blocking Abdb-Gal4 neurons led to increased bending amplitude upon touching the head. In the case of larval lateral rolling, larval tail paralysis by inhibition of Abdb-Gal4 neurons did not prevent the accomplishment of rolling, but resulted in slower rolling speed. Our work reveals that the contribution of Drosophila larval posterior VNC segments and corresponding body segments in the tail to locomotion is comprehensive but could be compensated at least partially by other body segments. We suggest that the decentralization in locomotion control with respect to animal body parts helps to maintain the robustness of locomotion in multi-segment animals.
摘要：
尾巴在许多动物的运动控制中起着重要作用。但是在有多个身体部分的动物中，后体节段和相应的神经支配神经元在运动控制中的作用尚不清楚。这里,使用果蝇幼虫作为模型动物，我们调查了后末端节段在各种运动模式中的作用，发现它们都参与其中。在向前爬行中，通过阻断VNC后段Abdb-Gal4标记的神经元而使幼虫尾巴麻痹，导致运动速度较慢，但并未阻止向前蠕动的开始。在向后爬行，尽管可以启动并持续向后蠕动波，但受Abdb-Gal4神经元抑制的幼虫无法产生有效的位移。在头部摆动的尾部运动不明显的地方，通过阻断Abdb-Gal4神经元来禁用幼虫尾巴，导致触摸头部时弯曲幅度增加。在幼虫横向滚动的情况下，通过抑制Abdb-Gal4神经元的幼虫尾部麻痹并不能阻止滚动的完成，但导致较慢的滚动速度。我们的工作表明，果蝇幼虫后部VNC节段和尾巴中相应的身体节段对运动的贡献是全面的，但至少可以由其他身体节段部分补偿。我们建议，相对于动物身体部位的运动控制分散有助于保持多段动物运动的鲁棒性。
