ROLE OF INTERNEURONAL CIRCUITS IN HUMAN SPINAL CORD INJU

神经元回路在人类脊髓损伤中的作用

• 批准号: 6529659
• 负责人: BRIAN D SCHMIT
• 金额: $ 25.38万
• 依托单位: REHABILITATION INSTITUTE OF CHICAGO D/B/A SHIRLEY RYAN ABILITYLAB
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-28 至 2005-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6529659
• 关键词: central neural pathway /tract; clinical research; electromyography; electrostimulus; human subject; interneurons; neuromuscular function; neuromuscular stimulator; spasm; spinal cord injury

Interneuronal pathways play a significant role in the origin of spasticity in spinal cord injury (SCI.). Following SCI, the interruption of key descending spinal pathways results in uncontrolled reflex movements of the legs. These reflex movements consist of coordinated flexion or extension of the hip, knee and ankle in response to specific exteroceptive or proprioceptive cues. We postulate that SCI releases functional interneuronal circuits, making them accessible to afferent inputs. These circuits include interneuronal pathways responsible for the well-know flexion withdrawal reflex, which Is exaggerated in SCI, and the emergence of a novel reflex response, the extensor spasm. Knowledge of the afferent pathways and interneuronal systems responsible for flexor spasms is based on this analogy to the flexion withdrawal reflex. However, there is virtually no information about the origins of extensor spasms in SCI. Our first aim is to test whether flexor spasms are peripherally mediated by load-sensitive muscle afferents of the flexors. We postulate that hvperexcitability of the interneuronal pathways associated with load sensitive afferents could produce self excitation, effectively establishing a positive feedback loop. This mechanism would provide an explanation for the prolonged, repetitive muscle activation associated with flexor spasms. We will test this hypothesis in SCI subjects by altering the muscle load during the flexor reflex using muscle stimulation and imposed movements. Effects will be measured using joint torque and electromyographic measurements. For extensor spasms, we hypothesize that the observed motor behavior results from the release of spinal locomotor pathways following SCI. We will test this hypothesis by investigating whether extensor spasms are modulated by afferent information from hip flexors and ankle extensors. Since the proprioceptive hip flexor afferents and group lb ankle extensor afferents play a prominent role in the modulation of locomotion, by analogy we expect to show that extensor spasms are the manifestation of these locomotor reflexes. Extensor spasms will be quantified using a novel apparatus that measures the joint torque response to imposed movement triggers. The principles developed in this study will form the basis for new treatment modalities for spasticity in spinal cord injury.

神经元途径在起源中起着重要作用 脊髓损伤的痉挛（科学）。在SCI之后，密钥的中断 下降的脊柱途径导致不受控制的反射运动 腿。这些反射运动包括协调的屈曲或扩展 应对特定的外部感受或本体感受，臀部，膝盖和脚踝 提示。我们假设SCI释放功能性的神经元电路，使 它们可以通过传入输入访问。这些电路包括神经元 负责聪明屈曲提取反射的途径，即 在SCI中夸张，以及新颖的反射响应的出现，延伸器 痉挛。了解传入途径和负责的神经元系统 对于屈肌痉挛是基于此类比屈曲提取反射。 但是，几乎没有有关伸肌痉挛起源的信息 在科幻。 我们的第一个目的是测试屈曲痉挛是否由外周介导 屈肌的负载敏感肌肉传入。我们假设 与负载敏感有关 传入可以产生自我激发，有效地建立一个积极的 反馈循环。这种机制将为延长， 重复的肌肉激活与屈曲痉挛有关。我们将测试这个 通过改变屈肌反射期间的肌肉负荷，SCI受试者的假设 使用肌肉刺激并施加运动。效果将使用 关节扭矩和肌电图测量。 对于伸肌痉挛，我们假设观察到的运动行为结果 从SCI之后的脊柱运动途径的释放中。我们将测试这个 假设通过研究伸肌痉挛是否通过传入调节 来自髋屈肌和脚踝伸肌的信息。由于髋关节 在 通过类比，运动的调制，我们希望表明延伸器痉挛 是这些运动反射的表现。伸肌痉挛将是 使用一种测量关节扭矩响应的新型设备进行量化 施加运动触发器。 本研究中发展的原理将构成新治疗的基础 脊髓损伤中痉挛的方式。