NEURONAL CONTROL OF LOCOMOTION IN LOBSTER, HOMARUS-AMERICANUS .1. MOTOR PROGRAMS FOR FORWARD AND BACKWARD WALKING
NEURONAL CONTROL OF LOCOMOTION IN LOBSTER, HOMARUS-AMERICANUS .1. MOTOR PROGRAMS FOR FORWARD AND BACKWARD WALKING
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DOI：
10.1007/bf00667782
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发表时间：
1977-01-01
期刊：
影响因子：
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通讯作者：
DAVIS, WJ
中科院分区：
文献类型：
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作者：
AYERS, JL;DAVIS, WJ
拴在跑步机上的龙虾逆着皮带运动的方向行走。通过这种方法，即使在没有视觉输入的情况下，也可以控制整个步进频率范围内的向前和向后运动。运动基质提供的被动牵引是行走的有效刺激，可能与前面描述的光运动通路并行运行，为运动行为提供正反馈强化。描述了龙虾行走腿的运动和肌肉解剖。基于同时从几个腿部肌肉的细胞外记录和运动图像分析，关节运动和肌肉协调的整体模式下，向前和向后行走描述。有些肌肉对向前行走具有协同作用，但对向后行走具有拮抗作用。类似的，对前侧侧走具有协同作用的运动对后侧侧走具有拮抗作用。对腿部运动和肌电图的定量分析表明，步行肌肉可细分为3个不同的功能类别：返回中风肌肉，其表现出相对恒定的持续时间，而与步频无关；爆发持续时间随步进频率线性变化的力量冲程肌肉；还有双功能肌肉，根据行走的方向，表现出回划肌或力量划肌的放电特征。一些证据表明，肢体提升运动神经元（或其中心前体细胞）是行走系统的中心起搏器，其他循环的腿部运动是附加在基本的上升/下降循环中，以适应行走的方向。被动牵引提供的本体感觉输入能够控制运动方向，并通过改变动力冲程爆发的持续时间来确定步进的周期性。
Lobsters tethered in place on a treadmill walk against the direction of belt movement. Forward and backward locomotion over the full range of step frequencies can be controlled by this method, even in the absence of visual input. The passive traction provided by a moving substrate is an effective stimulus for walking and presumably operates in parallel with previously described optomotor pathways to provide positive feedback reinforcement of locomotory behavior. The movements and muscular anatomy of a lobster walking leg are described. On the basis of simultaneous extracellular recording from several leg muscles, and motion picture analysis, the overall patterns of joint movement and muscular coordination underlying forward and backward walking are described. Some muscles that are synergic for forward walking are antagonistic for backward walking. Similarly movements that are synergic for lateral walking on the leading side are antagonistic for lateral walking on the trailing side. Quantitative analysis of leg movements and electromyograms showed that the walking muscles can be subdivided into 3 different functional classes: return stroke msucles, which exhibit bursts of relatively constant duration irrespective of step frequency; power stroke muscles in which burst duration varies linearly with step frequency; and bifunctional muscles which exhibit the discharge characteristics of either return or power stroke muscles, depending on the direction of walking. Several lines of evidence suggest that the limb elevator motoneurons (or their central antecedents) function as the central pacemaker of the walking system, and that other cyclic leg movements are appended to the basic elevation/depression cycle as appropriate to the direction of walking. Proprioceptive inputs provided by passive traction are capable of controlling the direction of locomotion and determining the periodicity of stepping by altering the duration of powerstroke bursts.