Multichannel Microstimulation of Primary Afferent Neurons to Restore Propriocepti

描述(申请人提供)：NIH神经假体计划在皮质控制神经假体领域取得了如此大的成功，以至于FDA已经批准了多项人体试验，以测试脑机接口(BMI)皮质植入物的安全性和有效性。BMI技术的一个重要应用是对假肢的直接皮质控制。该领域的最新进展催生了迄今开发出的功能最强的假肢，包括DEKA的“Luke Arm”和Johns Hopkins APL的“模块化假肢”。然而，在这一努力中的一个关键差距是缺乏体感反馈，这是支持假肢的本体感觉和触觉感觉所必需的。如果没有这些感觉，使用者永远不会从这些先进的肢体中获得最大的好处，因为如果没有感觉反馈，这些设备将仍然是麻木的、体外的“工具”，而不是完整的完全功能的肢体。我们的目标有两个：更好地了解感觉反馈的性质和外周感觉活动传递到初级体感皮质(S1)的方式，以及开发一个体感神经接口(SSNI)，为用户的神经假肢提供本体感觉反馈。我们先前提出，背根神经节(DRG)的初级传入微刺激(PAMS)可用于向中枢神经系统传递替代体感反馈。我们已经证明，在猫身上，PAMS可以从各种感觉模式招募少量的传入神经元(Gaant等人。2009)，并且这种刺激可以将有意义的活动传递给S1(Weber等人。2011年)。在这个动物模型的发展过程中取得的成功产生了许多新的问题和假设，并在此基础上提出了一系列新的实验。具体地说，这些实验的重点是表征PAMS的能力：1)当PAMS模式基于运动过程中记录在DRG中的神经活动时，PAMS模式向S1传递感觉信息；2)当PAMS模式基于捏造的静态和动态输入时，在麻醉猫中向S1传递可区分的感觉信息；以及3)在清醒的站立猫中向S1传递可区分的感觉信息，这有助于改变对地面支持扰动的姿势反应。这些实验的范围从进一步研究PAMS的能力到测试PAMS可预测地改变运动行为的能力。这项工作将进一步发展SSNI，这对基于BMI的假肢的未来至关重要，并解决有关感觉反馈在控制正常运动行为中的作用的基本问题。

DESCRIPTION (provided by applicant): The NIH neuroprosthesis program has fostered so much success in the area of cortically controlled neuroprostheses that the FDA has approved multiple human trials to test the safety and efficacy of cortical implants for brain machine interfaces (BMI). One important application of BMI technologies is the direct cortical control of prosthetic limbs. Recent advances in this field have led to the creation of the most capable prosthetic arms yet developed, including the DEKA 'Luke arm' and Johns Hopkins APL 'Modular Prosthetic Limb'. However, a critical gap in this effort is the lack of somatosensory feedback which is needed to support propriception and tactile sensations for the artificial limb. Without these sensations, users will never achieve maximum benefit from these advanced limbs, because without sensory feedback, these devices will remain as numb, extracorporeal 'tools', rather than integrated fully functional limbs. Our goals are twofold: to better understand the nature of sensory feedback and the way in which peripheral sensory activity is conveyed to primary somatosensory cortex (S1), and to develop a somatosensory neural interface (SSNI) that will provide the user with proprioceptive feedback for their neuroprosthesics limb. We have previously proposed that primary afferent microstimulation (PAMS) in the dorsal root ganglia (DRG) can be used to deliver surrogate somatosensory feedback to the central nervous system. We have demonstrated that in cats, PAMS can recruit small populations of afferents from a variety of sensory modalities (Gaunt et al. 2009) and that this stimulation can transmit meaningful activity to S1 (Weber et al. 2011). The success achieved during the development of this animal model generated a number of new questions and hypothesis upon which a series of new experiments are proposed. Specifically, these experiments focus on characterizing the ability of PAMS to 1) transmit sensory information to S1 in anesthetized cats when the PAMS patterns are based on neural activity recorded in the DRG during movement, 2) transmit discriminable sensory information to S1 in anesthetized cats when the PAMS patterns are based on fabricated static and dynamic inputs, and 3) transmit discriminable sensory information to S1 in awake standing cats, useful for modifying postural responses to ground support perturbations. These experiments range from further investigations of the capabilities of PAMS to testing the ability of PAMS to predictably modify motor behaviors. This work will further the development of a SSNI, critical for the future of BMI based prosthetic limbs, as well as address fundamental questions regarding the role of sensory feedback in the control of normal motor behaviors.