Targeting and Stimulating Cortical Area 3a to Restore Proprioception

项目摘要/摘要： 这项研究的更大目标是获得基础知识并论证 用皮质内微刺激(ICMS)恢复大脑皮层的臂肌力知觉 3a区。恢复这种特定的感官知觉对瘫痪的人来说尤其重要 使用大脑控制的周围神经功能性电刺激(FES)来 脊髓损伤后通过思维恢复手臂运动。对抗者的适当平衡 这一人群的肌肉力量对于维持肢体稳定性和最小化肌肉至关重要。 疲劳和电池耗尽。在目标1中，我们将使用灵长类成像和手术计划软件 将定制的慢性微丝电极阵列植入中央肘部深处 两只恒河猴的脑沟(总共四个半球)瞄准难以触及的目标 躯体感觉区3a。3a区从高尔基肌腱接收一系列本体感觉信号 器官(传递肌肉力量)和肌梭纤维(传递肌肉长度和 长度)，并应提供与优化FES最直接相关的肌肉特异性感知 手臂活动恢复。然而，已知的关于3a本体感觉编码的大部分 都是从急性录音中收集的。在本研究中，我们将使用慢性微电极 记录和一系列主动和被动的感觉运动任务，从几天到更完整 描述3a编码的特征。这些数据将被用来量化相对函数和 这些不同感觉编码特征在空间尺度上的空间分布 与通过ICMS恢复这些感觉有关。在第二个目标中，我们将使用一种新的力量 测试动物感知力主电极位置的ICMS能力的跟踪游戏 作为肌肉力量的增加。这个游戏的设计是为了防止动物仅仅学习 对一些不自然的“感觉”做出反应以获得奖励，并将证实受试者是 实际上在他们的运动规划中利用了力的感知。最后，我们将进行这些测试 使用一系列刺激参数将感知的力的大小量化为 刺激参数的作用。

Project Summary/Abstract: The larger goal of this study is to gain foundational knowledge and demonstrate the feasibility of restoring percepts of arm muscle force using intracortical microstimulation (ICMS) in cortical area 3a. Restoring this specific sensory percept is particularly important to paralyzed individuals that use brain-controlled functional electrical stimulation (FES) of their peripheral nerves to restore arm movements by thought after spinal cord injury. Appropriate balancing of antagonist muscle forces in this population is critical for maintaining limb stability and minimizing muscle fatigue and battery drain. In Aim 1, we will use primate imaging and surgical planning software to implant custom chronic microwire electrode arrays deep into the elbow region of the central sulcus of two Rhesus macaques (four hemispheres total) to target the difficult-to-reach somatosensory area 3a. Area 3a receives a range of proprioceptive signals from Golgi tendon organs (conveys muscle force) and muscle spindle fibers (conveys muscle length and change in length) and should provide muscle-specific percepts most directly relevant to optimizing FES arm movement restoration. However, most of what is known about 3a proprioceptive encoding has been collected from acute recordings. In this study, we will use chronic microelectrode recordings and a range of active and passive sensorimotor tasks across days to more fully characterize 3a encoding. These data will then be used to quantify the relative function and spatial distribution of these different sensory encoding characteristics on the spatial scale relevant to restoring these sensations via ICMS. In the second aim, we will use a novel force tracking game to test the animals' ability to perceive ICMS of force-dominant electrode locations as an increase in muscle force. This game is designed to prevent the animals from just learning to respond to some unnatural `sensation' for a reward and will verify that the subjects are actually utilizing the force percepts in their motor planning. Finally, we will conduct these tests using a range of stimulus parameters to quantify the magnitude of the force percepts as a function of stimulation parameters.