CORTICOSPINAL CONTROL OF FORELIMB MOVEMENT

前肢运动的皮质脊髓控制

• 批准号: 6188298
• 负责人: PAUL DAVID CHENEY
• 金额: $ 26.88万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-15 至 2003-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6188298
• 关键词: Primates; action potentials; biomechanics; brain mapping; cell population study; cingulate gyrus; electrodes; electromyography; electrostimulus; joints; limb movement; magnetic resonance imaging; motor cortex; muscle function; psychomotor function; pyramidal tracts; wakefulness

DESCRIPTION (Adapted From The Applicant's Abstract): This is a proposal requesting five years of support for work concerned with the synaptic and functional organization of frontal lobe cortical areas in the control of forelimb movements in primates. In recent years, our concepts about frontal lobe motor areas and corticospinal output organization have changed dramatically. Information about the synaptic connections of single corticospinal cells has shown clearly that these cells typically influence not just one muscle but combinations of muscles as functional muscle synergies. Moreover, the existence of a remarkable number of discrete premotor areas in the frontal lobe of primates has become clear, each with its own complement of corticospinal neurons. In this application we propose to build upon our previous studies concerning the contribution of the cortical motor areas to forelimb movement in primates. This proposal focuses on two major issues. The first builds upon our recent finding that a large fraction (45%) of corticomotoneuronal (CM) cells engaged in a reach and prehension task simultaneously facilitated or suppressed a combination of both proximal and distal muscles in spike triggered averages of EMG activity (McKiernan et al.,1998). These combinations of CM cell target muscles represent multi-joint, functional muscle synergies underlying basic coactivation patterns observed in proximal and distal muscle during reach and prehension movements of the forelimb. A central remaining question concerns the functional importance of the cell's distal and proximal target muscles. Will such cells only be activated for tasks in which the distal and proximal muscles are coactivated as a synergy? The second issue we wish to address concerns the mounting evidence from mostly anatomical studies favoring the existence of multiple, discrete corticospinal representations of limb muscles within the frontal cortex of primates. In addition to a proposed double representation of distal muscles in primary motor cortex, no less than six premotor areas have been suggested based on anatomical labeling of corticospinal neurons and other anatomical studies. These include two premotor areas in the lateral hemisphere, SMA and three areas buried in the cingulate gyrus. Although the presence of substantial corticospinal projections has prompted speculation that these areas represent parallel channels for direct access to motoneurons and movement control, there have been few physiological studies of the efficacy and characteristics of these corticospinal projections in comparison to those from primary motor cortex. The goal of this proposal will be to apply the techniques of spike and stimulus triggered averaging of EMG activity to map and assess the functional nature of these multiple corticospinal forelimb representations.

描述（改编自申请人的摘要）： 这是一项请求为与以下方面有关的工作提供五年支持的提案： 额叶皮质区的突触和功能组织 灵长类动物前肢运动的控制。近年来，我们的理念 额叶运动区和皮质脊髓输出组织发生了变化 戏剧性地。有关单个突触连接的信息 皮质脊髓细胞已清楚地表明这些细胞通常不影响 只有一块肌肉，但肌肉的组合作为功能性肌肉的协同作用。 此外，存在大量离散的运动前区 灵长类动物的额叶已经变得清晰，每种​​额叶都有自己的补充 皮质脊髓神经元。在此应用程序中，我们建议以我们的 先前关于皮质运动区对大脑功能的贡献的研究 灵长类动物的前肢运动。该提案主要关注两个主要问题。这 首先基于我们最近的发现，很大一部分 (45%) 参与触及和抓取任务的皮质运动神经元 (CM) 细胞 同时促进或抑制近端和 尖峰中的远端肌肉触发肌电图活动的平均值（McKiernan 等 等，1998）。这些 CM 细胞目标肌肉的组合代表多关节、 功能性肌肉协同作用是观察到的基本共激活模式的基础 伸手和抓握运动期间的近端和远端肌肉 前肢。剩下的一个核心问题涉及功能重要性 细胞的远端和近端目标肌肉。这样的细胞只会 激活远端和近端肌肉共同激活的任务 协同作用？我们希望解决的第二个问题涉及越来越多的证据 大多数解剖学研究支持存在多个离散的 额叶皮层内肢体肌肉的皮质脊髓表征 灵长类动物。除了提出的远端肌肉的双重表示之外 初级运动皮层，根据建议，至少有六个运动前区 皮质脊髓神经元的解剖标记和其他解剖学研究。 其中包括外侧半球的两个运动前区域、SMA 和三个区域 埋藏于扣带回。尽管存在大量的 皮质脊髓投射引发了人们的猜测，这些区域代表 用于直接访问运动神经元和运动控制的并行通道，有 关于其功效和特性的生理学研究很少 这些皮质脊髓投射与初级运动的投射相比 皮质。该提案的目标是应用尖峰技术和 刺激触发肌电图活动的平均，以绘制和评估功能 这些多个皮质脊髓前肢表征的性质。