[医学]北大神经生物学课件7-1神经系统对运动的调节.ppt

Central Nervous System Control of Movement XING, GUOGANG(邢国刚), MD. Ph.D. 北京大学 神经科学研究所 Neuroscience Research Institute, Peking University Email address: ggxing@bjmu.edu.cn Introduction 生命在于运动…… 运动是动物维系个体生存和种族繁衍的基本功能之一 How does a coordinated movement achieved ? The motor control hierarchy have three levels The highest level－ strategy Represented by the association areas of neocortex and basal ganglia of the forebrain Is concerned with strategy: The goal of the movement and the movement strategy that best achieves the goal The motor control hierarchy have three levels The middle level－tactics Represented by the motor cortex and cerebellum Is concerned with tactics The sequences of muscle contractions Arranged in space and time Required to smoothly and accurately achieve the strategic goal The motor control hierarchy have three levels The lowest level－ execution Represented by the brain stem and spinal cord Is concerned with execution Action of the motor neuron and interneuron pools that generate the goal-directed movement and make any necessary adjustments of posture Overview 脊髓内的“下运动神经元(Lower neurons)”，除了受到脊髓内局部环路的影响外，还受到大脑皮层运动区及脑干中许多“上运动神经元(Upper neurons)”的支配和协调 基底神经节和小脑则向那些上运动神经元提供某种感觉、认知或感性的信息，使运动更加精确和协调  Part 1 Spinal Control of Movement Introduction “running around like a chicken with its head cut off” The rhythmic movements could be elicited in the hind legs of cats and dogs long after their spinal cords had been severed from the rest of the central nervous system –Charles Sherington Graham Brown (English) The importance of circuitry within the spinal cord for the coordinated control of movements Spinal circuitry control of movement Spinal motor neurons Alpha motor neurons Innervate skeletal muscle (extrafusal muscle) Function: directly command muscle contract Gamma motor neurons Innervate muscle spindle (intrafusal muscle) Function: regulating the muscle spindle Interneurons Allows coordinated motor programs to be