SENSORY AND MOTOR INTEGRATION IN THE SPINAL CORD

脊髓中的感觉和运动整合

• 批准号: 3417697
• 负责人: Paul S. Stein
• 金额: $ 21.09万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-07-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3417697
• 关键词: Chelonia; afferent nerve; aminoacid inhibitor; axon; cutaneous sensory nerve; electrophysiology; glutamate receptor; horseradish peroxidase; interneurons; limbs; motor neurons; reflex; sensory feedback; single cell analysis; spinal cord mapping; spinal nerves

We will study the rostral scratch, the pocket scratch, and the flexion reflex in the turtle with a complete transection of the spinal cord just posterior to the forelimb enlargement. Each of these cutaneous reflexes displays a distinct pattern of hindlimb motor neuron activation in response to tactile stimulation within a specific receptive field. We will record motor neuron activation patterns in a preparation immobilized by neuromuscular blockade. Spinal cord circuitry in this preparation, in the absence of movement-related sensory feedback, selects and generates an appropriate motor pattern for each specific stimulus: the circuitry makes a motor pattern decision and then produces that motor pattern. Our experiments will reveal spinal cord neuronal mechanism responsible for these processes. We will use several experimental strategies to study these mechanisms. First, we will study the anatomical and physiological properties of a specific class of spinal cord neuron, the set of propriospinal neurons with descending axons. We will use these data to test specific hypotheses about the characteristics of spinal neurons involved in the selection and generation of scratch reflex motor patterns. Second, we will continue our characterization of the contributions of glutamate receptors to cutaneous reflexes. We will examine the relative contributions of non-NMDA and NMDA receptors to each component of the flexion reflex. We will determine the contribution of each class of glutamate receptors to rostral scratch motor pattern generation. Third, we will measure the contribution of glutamate receptors to the activation of propriospinal neurons involved in the flexion reflex and in the rostral scratch reflex. In each specific aim, we will obtain information concerning the neuronal mechanisms responsible for cutaneous sensorimotor integration in the spinal cord. Turtle spinal cord is similar to that of other vertebrates, including humans. The mechanisms we will reveal may serve as working hypotheses for studies of spinal cord sensorimotor integration in other vertebrates.

我们将研究吻侧抓伤、口袋抓伤和屈曲 脊髓完全横断的乌龟的反射 前肢后方膨大。 这些皮肤反射 显示出独特的后肢运动神经元激活反应模式 特定感受野内的触觉刺激。 我们将记录 固定化制剂中的运动神经元激活模式 神经肌肉阻滞。 在此准备中的脊髓电路，在 缺乏与运动相关的感觉反馈，选择并生成 针对每个特定刺激的适当运动模式：电路使 运动模式决策，然后产生该运动模式。 我们的 实验将揭示脊髓神经元机制 这些过程。 我们将使用几种实验策略来研究这些机制。 首先，我们将研究动物的解剖学和生理学特性。 特定类别的脊髓神经元，即具有以下特征的一组固有脊髓神经元 下降轴突。 我们将使用这些数据来检验有关的具体假设 参与选择和选择的脊髓神经元的特征 产生刮擦反射运动模式。 其次，我们将继续我们的 谷氨酸受体对皮肤的贡献的表征 反射。 我们将研究非 NMDA 和 NMDA 的相对贡献 屈曲反射每个部分的感受器。 我们将确定 各类谷氨酸受体对吻端抓挠运动的贡献 模式生成。 第三，我们来衡量谷氨酸的贡献 参与激活本体脊髓神经元的受体 屈曲反射和头端抓挠反射。 在每个具体目标中，我们将获得有关神经元的信息 负责脊髓中皮肤感觉运动整合的机制 绳索。 乌龟的脊髓与其他脊椎动物的脊髓相似， 包括人类。 我们将揭示的机制可能会发挥作用 其他脊髓感觉运动整合研究的假设 脊椎动物。