Chung Bryce, Bacqué-Cazenave Julien, Cofer David W, Cattaert Daniel, Edwards Donald H
Neuroscience Institute, Georgia State University, Atlanta, Georgia; and.
Institute de Neurosciences Cognitives et Intégratives d'Aquitaine, University of Bordeaux 1, Talence, France.
J Neurophysiol. 2015 Mar 15;113(6):1763-71. doi: 10.1152/jn.00248.2014. Epub 2014 Dec 24.
The effect of proprioceptive feedback on the control of posture and locomotion was studied in the crayfish Procambarus clarkii (Girard). Sensory and motor nerves of an isolated crayfish thoracic nerve cord were connected to a computational neuromechanical model of the crayfish thorax and leg. Recorded levator (Lev) and depressor (Dep) nerve activity drove the model Lev and Dep muscles to move the leg up and down. These movements released and stretched a model stretch receptor, the coxobasal chordotonal organ (CBCO). Model CBCO length changes drove identical changes in the real CBCO; CBCO afferent responses completed the feedback loop. In a quiescent preparation, imposed model leg lifts evoked resistance reflexes in the Dep motor neurons that drove the leg back down. A muscarinic agonist, oxotremorine, induced an active state in which spontaneous Lev/Dep burst pairs occurred and an imposed leg lift excited a Lev assistance reflex followed by a Lev/Dep burst pair. When the feedback loop was intact, Lev/Dep burst pairs moved the leg up and down rhythmically at nearly three times the frequency of burst pairs when the feedback loop was open. The increased rate of rhythmic bursting appeared to result from the positive feedback produced by the assistance reflex.
在克氏原螯虾（Procambarus clarkii，Girard）中研究了本体感觉反馈对姿势和运动控制的影响。将一只分离的小龙虾胸神经索的感觉神经和运动神经连接到一个小龙虾胸部和腿部的计算神经力学模型上。记录的提肌（Lev）和降肌（Dep）神经活动驱动模型中的Lev和Dep肌肉使腿部上下移动。这些运动释放并拉伸了一个模型拉伸感受器，即基节弦音器（CBCO）。模型中CBCO长度的变化导致真实CBCO发生相同的变化；CBCO传入反应完成了反馈回路。在静止准备状态下，施加的模型腿部抬起会在Dep运动神经元中诱发阻力反射，使腿部回落。一种毒蕈碱激动剂氧化震颤素会诱导一种活跃状态，在此状态下会出现自发的Lev/Dep爆发对，并且施加的腿部抬起会激发Lev辅助反射，随后是Lev/Dep爆发对。当反馈回路完整时，Lev/Dep爆发对使腿部以几乎是反馈回路开放时爆发对频率的三倍的节奏上下移动。节律性爆发速率的增加似乎是由辅助反射产生的正反馈导致的。
