Neural Control of a Context-Dependent Molluscan Feeding Muscle

神经系统是如何控制肌肉的功能随其机械环境而变化的？为了回答这个问题，Chiel博士正在研究一种动物的肌肉，这种动物是海洋软体动物，它的生物力学和神经控制都很容易通过实验分析。为了验证这一假设，即肌肉I1/ I3在进食过程中的功能取决于它们的机械环境，他将研究I1/ I3相对于完整的进食器官中其他肌肉的位置变化，使用MRI喂养动物，以及构建详细的运动学模型。利用神经生理学技术，他还将确定动物的神经系统是否利用I1/I3肌肉的上下文相关特性来产生不同的运动，而不是在咀嚼过程中吞咽。拟议的研究可能会提出原则，澄清高等脊椎动物以及无脊椎动物中上下文相关肌肉的控制。这些研究将导致新的MRI成像技术的发展，可应用于许多其他自由移动的生物结构。最后，这些研究提出了一个更丰富的运动控制的观点，其中运动模式不是纯粹由神经系统的活动驱动的，而是由身体的动力学以及神经系统的动力学主动构建的。

How does the nervous system control muscles whose function changes with their mechanical context? To answer this question, Dr. Chiel is studying muscles in an animal, the marine mollusk Aplysia californica, whose biomechanics and neural control are both tractable to experimentalanalysis. To test the hypothesis that the function of the muscles I1/ I3 during feeding are dependent on their mechanical context, he will study the changing position of I1/ I3 relative to other muscles in the feeding apparatus in intact, feeding animals using MRI, as well as constructing a detailed kinematic model. Using neurophysiological techniques, he will alsodetermine whether the nervous system of the animal exploits the context-dependent properties of the I1/I3 muscles to generate different movements during biting as opposed to swallowing.The proposed research is likely to suggest principles that will clarify the control of context-dependent muscles in higher vertebrates as well as in invertebrates. These studies will lead to the development of novel MRI imaging techniques that may be applied to many other freelymoving biological structures. Finally, these studies suggest a richer view of motor control, in which motor patterns are not purely driven by activity of the nervous system, but are actively constructed from the dynamics of the body as well as the dynamics of the nervous system.