Control of Reafference in Posture and Locomotion

阻力反射帮助动物对抗可能移动其四肢的外力，因此它们有助于保持稳定的姿势。在随意运动期间，这些相同的阻力反射必须被禁用或逆转以允许运动发生。本研究探讨了阻力反射是如何组织的，使动物保持静态姿势，以及它们是如何在自愿运动开始时被禁用并转化为辅助反射的。虽然这些问题已经在脊椎动物、昆虫和甲壳类动物中得到了解决，但答案还远远没有完成。 当前研究中的问题将在小龙虾中解决，因为腿部运动的相关电路已经在一组识别的感觉神经元，中间神经元和运动神经元及其突触相互作用方面进行了描述。研究人员将使用三种方法：（i）体内运动分析和神经记录;（ii）混合体外制备/神经力学模型;（iii）小龙虾身体和神经系统的神经力学模拟。这种方法将揭示动物如何控制其反射，以帮助稳定姿势，并协助水下和陆地上的自愿运动，其中外部力量的设置非常不同。这里发现的机制很可能被其他有腿动物使用。该方法采用了主要研究者实验室开发的两种新工具，AnimatLab神经机械模拟软件和将模型与实验准备的神经系统联系起来的混合神经机械接口。 AnimatLab可在www.animatlab.com上免费获得，混合界面将被制成商业级电子仪器。这项研究将为本科生和研究生提供神经生理学、行为分析和计算神经科学方面的培训，其中包括代表性不足的人群。 这些学生将参与帮助教授夏季B.R.A.I.N.的相关部分。课程在格鲁吉亚州立大学为优秀的本科生来自全国各地。

Resistance reflexes help an animal to counter external forces that would move its limbs, thus they help maintain a stable posture. During voluntary movement, those same resistance reflexes must be disabled or reversed to allow the movement to occur. This study asks how the resistance reflexes are organized to allow an animal to maintain a static posture, and how they are disabled and transformed into assistance reflexes at the onset of voluntary movements. While these questions have been approached in vertebrates, insects and crustaceans, answers are far from complete. The questions in the current study will be addressed in the crayfish because relevant circuitry for leg movements has been described in terms of a set of identified sensory neurons, interneurons and motor neurons, and their synaptic interactions. The investigators will use three approaches: (i) in vivo motion analysis and nerve recordings; (ii) a hybrid in vitro preparation/neuromechanical model; and (iii) a neuromechanical simulation of the crayfish body and nervous system. This approach will reveal how the animal controls its reflexes to help stabilize posture and assist voluntary movements underwater and on land, where the set of external forces are very different. The mechanisms discovered here are likely to be used by other legged animals. The approach employs two new tools developed by the principal investigator's laboratory, the AnimatLab neuromechanical simulation software and the hybrid neuromechanical interface that links a model to the nervous system of the experimental preparation. AnimatLab is freely available at www.animatlab.com, and the hybrid interface will be made into a commercial-grade electronic instrument. The research will provide training in neurophysiology, behavioral analysis and computational neuroscience to undergraduate and graduate students who include members of underrepresented populations. Those students will participate in helping to teach relevant portions of the summer B.R.A.I.N. course at Georgia State University for outstanding undergraduates from around the country.