Known and unexpected constraints evoke different kinematic, muscle, and motor cortical neuron responses during locomotion.
Known and unexpected constraints evoke different kinematic, muscle, and motor cortical neuron responses during locomotion.
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DOI：
10.1111/ejn.13053
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发表时间：
2015-11
期刊：
影响因子：
--
通讯作者：
Beloozerova IN
中科院分区：
文献类型：
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作者：
Stout EE;Sirota MG;Beloozerova IN
在复杂的自然环境中航行时，人和动物必须在环境变化时适应他们的运动。这种适应的神经机制知之甚少，特别是在意想不到的限制，必须迅速适应。在这项研究中，我们记录了猫沿着沿着升高的水平梯子行走的前肢相关运动学、肌肉活动和运动皮层神经元的活动，这是一项复杂的运动任务，需要精确的肢体放置。其中一个横梁是机动化的，和位移之前，猫踩在梯子上或在不同的点沿着猫的进展在梯子上，无论是朝向或远离猫。我们发现，当横梁位移之前，猫踩在梯子上，运动学修改是复杂的，涉及改变所有前肢关节的动力学。当横档意外位移，而猫在梯子上，运动学修改是最小的，主要涉及远端关节。M. triceps和M.指总伸肌移位方向不同。在测试的151个神经元中，69%对至少一种条件做出反应;然而，当横挡位移出乎意料时，神经元更有可能做出反应。大多数情况下，他们在摇摆阶段做出反应。这些结果表明，不同的神经机制和电机控制策略被用来克服运动的限制，这取决于它们是否是已知的或意外出现。
During navigation through complex natural environments, people and animals must adapt their movements when the environment changes. The neural mechanisms of such adaptations are poorly understood, especially in respect to constraints that are unexpected and must be adapted to quickly. In this study, we recorded forelimb-related kinematics, muscle activity, and the activity of motor cortical neurons in cats walking along a raised horizontal ladder, a complex locomotion task requiring accurate limb placement. One of the crosspieces was motorized, and displaced before the cat stepped on the ladder or at different points along the cat’s progression over the ladder, either toward or away from the cat. We found that when the crosspiece was displaced before the cat stepped onto the ladder, kinematic modifications were complex and involved alterations of dynamics of all forelimb joints. When the crosspiece displaced unexpectedly while the cat was on the ladder, kinematic modifications were minimalistic and primarily involved distal joints. The activity of M. triceps and M. extensor digitorum communis differed based on the direction of displacement. Out of 151 neurons tested, 69% responded to at least one condition; however, neurons were significantly more likely to respond when crosspiece displacement was unexpected. Most often they responded during the swing phase. These results suggest that different neural mechanisms and motor control strategies are used to overcome constraints for locomotor movements depending on whether they are known or unexpectedly emerge.