Movements generated by intraspinal microstimulation in the intermediate gray matter of the anesthetized, decerebrate, and spinal cat
Movements generated by intraspinal microstimulation in the intermediate gray matter of the anesthetized, decerebrate, and spinal cat
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DOI：
10.1139/y04-079
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发表时间：
2004-08-01
影响因子：
2.1
通讯作者：
Prochazka, A
中科院分区：
文献类型：
--
作者：
Mushahwar, VK;Aoyagi, Y;Prochazka, A
腰骶段脊髓的中间层被认为含有少量专门的神经元回路，这些回路构成了运动构造的基本元素(“运动基元”)。我们的目的是研究这些假想回路的性质和状态依赖性，并与直接刺激神经或肌肉引起的运动进行比较。将用于椎管内微刺激(ISMS)的微丝植入腰椎膨大的中间椎板。将ISMS诱发的运动矢量与通过肌肉和神经电极刺激诱发的运动矢量进行比较，猫麻醉后去大脑，最后棘化。在麻醉状态下，ISMS以及神经和肌肉刺激可以引起类似的动作，这些动作覆盖了肢体的整个工作空间。ISM诱发的动作与附近运动神经元池的动作有关。然而，在去大脑和棘化后，ISMS诱发的运动以屈曲为主，伸肌运动很少。这表明，中间板层神经元网络的输出在很大程度上取决于下行输入和脊髓的状态。通常情况下，产出也取决于刺激强度。这些实验表明，脊髓中间区和腹侧区的神经元间回路重叠，它们的功能可能是灵活地处理反射和下行活动，以激活附近的运动神经元池。
The intermediate laminae of the lumbosacral spinal cord are suggested to contain a small number of specialized neuronal circuits that form the basic elements of movement construction ("movement primitives"). Our aim was to study the properties and state dependence of these hypothesized circuits in comparison with movements elicited by direct nerve or muscle stimulation. Microwires for intraspinal microstimulation (ISMS) were implanted in intermediate laminae throughout the lumbosacral enlargement. Movement vectors evoked by ISMS were compared with those evoked by stimulation through muscle and nerve electrodes in cats that were anesthetized, then decerebrated, and finally spinalized. Similar movements could be evoked under anesthesia by ISMS and nerve and muscle stimulation, and these covered the full work space of the limb. ISMS-evoked movements were associated with the actions of nearby motoneuron pools. However, after decerebration and spinalization, ISMS-evoked movements were dominated by flexion, with few extensor movements. This indicates that the outputs of neuronal networks in the intermediate laminae depend significantly on descending input and on the state of the spinal cord. Frequently, the outputs also depended on stimulus intensity. These experiments suggest that interneuronal circuits in the intermediate and ventral regions of the spinal cord overlap and their function may be to process reflex and descending activity in a flexible manner for the activation of nearby motoneuron pools.