Rapid Adaptation to Changing Mechanical Load by Ordered Recruitment of Identified Motor Neurons
Rapid Adaptation to Changing Mechanical Load by Ordered Recruitment of Identified Motor Neurons
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DOI：
10.1523/eneuro.0016-20.2020
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发表时间：
2020-05-01
期刊：
影响因子：
3.4
通讯作者：
Chiel, Hillel J.
中科院分区：
文献类型：
--
作者：
Gill, Jeffrey P.;Chiel, Hillel J.
当它们与环境互动并遇到挑战时，动物会随时调整自己的行为以保持任务适应性。这种自适应运动控制的动态过程发生在神经系统中，但对身体生物力学的理解对于正确解释行为结果至关重要。为了研究动物如何应对不断变化的任务条件，我们使用了一个模型系统，在该系统中，已识别的神经元的功能作用和相关的生物力学得到了很好的理解，并且可以在行为完整的动物中进行研究：在海洋软体动物中喂养。我们监测的运动神经元输出的喂养电路作为完整的动物均匀的食物刺激下卸载和加载的条件下，我们测量的收缩力加载吞咽。我们观察到一种以前未描述的力产生模式，这可以在适当的生物力学背景下通过几个关键的运动神经元的活动来解释。我们发现，当遇到负荷，动物招募识别的牵开肌运动神经元更长的时间和更高的频率，以增加收缩力的持续时间。我们的研究结果确定了一种模式，动物鲁棒地调整行为，以适应他们的环境，这是实验上易于进一步的机制研究。
As they interact with their environment and encounter challenges, animals adjust their behavior on a moment-to-moment basis to maintain task fitness. This dynamic process of adaptive motor control occurs in the nervous system, but an understanding of the biomechanics of the body is essential to properly interpret the behavioral outcomes. To study how animals respond to changing task conditions, we used a model system in which the functional roles of identified neurons and the relevant biomechanics are well understood and can be studied in intact behaving animals: feeding in the marine mollusc Aplysia. We monitored the motor neuronal output of the feeding circuitry as intact animals fed on uniform food stimuli under unloaded and loaded conditions, and we measured the force of retraction during loaded swallows. We observed a previously undescribed pattern of force generation, which can be explained within the appropriate biomechanical context by the activity of just a few key, identified motor neurons. We show that, when encountering load, animals recruit identified retractor muscle motor neurons for longer and at higher frequency to increase retraction force duration. Our results identify a mode by which animals robustly adjust behavior to their environment, which is experimentally tractable to further mechanistic investigation.