Neural Processing of Native and Prosthetic Vestibular Signals for Postural Control

摘要 这个项目的主要目标是加深我们对前庭系统的贡献的理解。 平衡控制，特别是驱动对姿势扰动的反射性反应的神经机制。 视觉、本体感觉和前庭信号是感知身体位置和 保持平衡。然而，姿势控制的中枢神经机制仍然难以捉摸。 研究需要记录自由行为时脑干中的单个神经元。为了更好地理解 前庭部分的中枢姿势控制，我将首先在动物身上建立基线姿势反应 模型，恒河猴，这已被证明是一个有价值的模型，以了解神经控制的 人的前庭功能和加工。然后我将描述在这些过程中的行为和神经反应 健康动物、双侧前庭缺失动物和前庭缺失动物的姿势稳定行为 使用前庭假体进行功能替换。本项目的目标1是描述行为 对支持表面扰动的响应。在姿势摄动实验中，动物要适应 安装在六自由度六足运动平台上的行为室。六足动物送来 支持表面扰动，并使用惯性测量单元、测力板、 和无标记视频运动跟踪。这些扰动在正常和双侧前庭缺失中反复出现。 动物的姿势反应被量化，以建立前庭贡献的模型 来平衡控制。目标2是描述驱动姿势反射的前庭敏感神经元的反应 以支持表面扰动。我将在无线、高密度神经记录方面利用新兴技术 描述前庭核团(VN)神经元对姿势扰动的反应，以便 阐明由VN细胞驱动的前庭-脊髓反射对姿势矫正的贡献。 最后，对于目标3，我将用一只装有多通道的动物重复这些实验和录音 前庭假体，以评估前庭假体引起的姿势改善，以及 对假体提供的新的和/或修改的前庭输入的神经适应。这部作品具有 也可能有助于我们理解前庭感觉在保持直立姿势中的作用 AS通过提供最佳数据改善双侧前庭缺失患者的生活质量 前庭假体的调制策略。

ABSTRACT The primary goal of this project is to further our understanding of the contribution of the vestibular system to balance control, particularly the neural mechanisms driving reflexive responses to postural perturbations. Visual, proprioceptive, and vestibular signals are the primary means for sensing the position of the body and maintaining balance. However, the central neural mechanisms of postural control remain elusive, as such research requires recording single neurons in the brainstem during free behavior. In order to understand the vestibular component of central postural control, I will first establish baseline postural responses in an animal model, the rhesus macaque, which has proven to be a valuable model for understanding the neural control of human vestibular function and processing. I will then characterize behavioral and neural responses during these posture-stabilizing behaviors in healthy animals, bilateral vestibular loss animals, and vestibular loss animals with replacement-of-function using a vestibular prosthesis. Aim 1 of this project is to characterize behavioral responses to support surface perturbations. For postural perturbation experiments, the animal is acclimated to a behavioral chamber mounted on a 6-degree-of-freedom hexapod motion platform. The hexapod delivers support surface perturbations, and the animal’s motion is tracked using inertial measurement units, a force plate, and markerless video motion tracking. These perturbations are repeated in normal and bilateral vestibular loss animals, and the animals’ postural responses are quantified in order to build a model of the vestibular contribution to balance control. Aim 2 is to characterize responses of vestibular-sensitive neurons that drive postural reflexes to support surface perturbations. I will leverage emerging technology in wireless, high-density neural recording to characterize the responses of neurons in the vestibular nuclei (VN) to postural perturbations in order to elucidate the contribution of vestibulo-spinal reflexes, which are driven by VN cells, to postural corrections. Finally, for Aim 3 I will repeat these experiments and recordings with an animal fitted with a multichannel vestibular prosthesis in order to assess improvements in posture caused by the vestibular prosthesis, as well as neural adaptation to novel and/or modified vestibular inputs delivered by the prosthesis. This work has the potential to contribute to our understanding of the role of vestibuloception in maintaining upright posture, as well as improve quality-of-life for patients experiencing bilateral vestibular loss by providing data on the best modulation strategies for vestibular prostheses.