Rapid correction of aimed movements by summation of force-field primitives
Rapid correction of aimed movements by summation of force-field primitives
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DOI：
10.1523/jneurosci.20-01-00409.2000
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发表时间：
2000-01-01
影响因子：
5.3
通讯作者：
Giszter, SF
中科院分区：
文献类型：
--
作者：
Kargo, WJ;Giszter, SF
脊髓回路形成运动结构的构建块。在青蛙中，这种积木被描述为等距力场。微刺激研究表明，单独的力场可以通过矢量求和来组合。理论上，几种力场类型的总和和缩放可以产生与肢体行为相关的大范围动态力场结构。我们第一次测试了力场总和是否是青蛙真实的肢体行为的基础。我们研究了组织的纠正反应，规避路径障碍物在后肢擦拭轨迹。在擦拭过程中，通过皮肤反馈信号障碍物碰撞在线触发校正响应。校正响应激活了一个力场，该力场与擦拭过程中激活的一系列力场相加。擦拭电机模式内的冲击力和冲击时间都缩放了诱发校正响应幅度。然而，校正反应的持续时间是恒定的，并且与擦拭的不同阶段中激活的其他肌肉的持续时间相似。因此，我们的研究结果证实，力场的总和和缩放发生在真实的肢体行为，力场代表固定时间的运动元素，这些运动元素结合在链和组合的反馈和中央运动程序的相互作用。
Spinal circuits form building blocks for movement construction. In the frog, such building blocks have been described as isometric force fields. Microstimulation studies showed that individual force fields can be combined by vector summation. Summation and scaling of a few force-field types can, in theory, produce a large range of dynamic force-field structures associated with limb behaviors. We tested for the first time whether force-field summation underlies the construction of real limb behavior in the frog. We examined the organization of correction responses that circumvent path obstacles during hindlimb wiping trajectories. Correction responses were triggered on-line during wiping by cutaneous feedback signaling obstacle collision. The correction response activated a force field that summed with an ongoing sequence of force fields activated during wiping. Both impact force and time of impact within the wiping motor pattern scaled the evoked correction response amplitude. However, the duration of the correction response was constant and similar to the duration of other muscles activated in different phases of wiping. Thus, our results confirm that both force-field summation and scaling occur during real limb behavior, that force fields represent fixed-timing motor elements, and that these motor elements are combined in chains and in combination contingent on the interaction of feedback and central motor programs.