Maintaining balance in an unstable environment: A central role for the vestibular system

在不稳定的环境中保持平衡：前庭系统的核心作用

• 批准号: RGPIN-2020-05391
• 负责人: Barthélemy, Dorothy
• 金额: $ 2.04万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=717617
• 关键词: Maintaining; balance; unstable; environment; central

Every winter, Canadians must employ their best balance control efforts, as the sidewalks resemble a giant ice rink, and simply walking to the corner of the street can resemble an artistic skating routine. Balance control is thus an essential part of our daily lives, but the neuronal mechanisms that enable those behaviours remain poorly understood. The long-term objective of my research program is to identify the nature of neuronal interactions that enable balance control in humans. In the next 5 years, I will specifically assess neuronal interactions involving the vestibular system. Indeed, the vestibular system was shown to be a key component of the balance control system, yet the actual mechanisms underlying its contribution are largely unknown. My proposed research program aims at filling this gap in knowledge and will investigate key neuronal interactions that enable balance control. In the first aim, we will assess the influence of the vestibular system on neurons located in the spinal cord during unexpected backward tilt of the base of support. Our HYPOTHESIS is that the vestibular system is involved in the generation of the postural reactions following perturbation by facilitating specific interneurons in the spinal cord, the Ia inhibitory interneurons, which enable contraction from one muscle while the opposing muscle is relaxed. This enables a fluid movement and rapid postural reactions. In the second aim, we will assess the role of motor cortex in modulating the vestibular output during standing. Our HYPOTHESIS is that the cortex controls balance and postural reactions in part by modulating the vestibular system, forming a hierarchical neuronal network to control balance. We further hypothesize that when individuals will be standing on an unstable surface, the motor cortex will be more active to maintain balance and prevent a fall. This will increase its influence. In the third aim, we will determine the influence of sensory information from our body (somatosensory) and of the vestibular system on the voluntary activation of our muscles (motor output) during balance skill acquisition. Our HYPOTHESIS is that both the vestibular and somatosensory systems help shape the motor output during balance training to acquire a new balance skill. Overall, the proposed research program will further our knowledge on key neuronal interactions that enable balance control, and acquisition of a balance skills. It will further inform us on how sensory information from our body and from our vestibular system are included into the central nervous system to enable balance control. This work could have potentially important applications in terms of preventing falls in an increasingly aging population and to promote different training paradigms in athletes who require exceptional balance control (such as gymnasts). This work may also lead to technological developments to support for example adaptation of astronauts during space exploration.

每年冬天，加拿大人都必须尽最大努力控制平衡，因为人行道就像一个巨大的溜冰场，只要走到街角就可以像艺术滑冰一样。因此，平衡控制是我们日常生活的重要组成部分，但实现这些行为的神经机制仍然知之甚少。我的研究计划的长期目标是确定能够实现人类平衡控制的神经元相互作用的本质。 在接下来的5年里，我将专门评估涉及前庭系统的神经元相互作用。事实上，前庭系统被证明是平衡控制系统的关键组成部分，但其作用背后的实际机制在很大程度上尚不清楚。我提出的研究计划旨在填补这一知识空白，并将研究实现平衡控制的关键神经元相互作用。 第一个目标是，我们将评估支撑底座意外向后倾斜时前庭系统对脊髓神经元的影响。我们的假设是，前庭系统通过促进脊髓中的特定中间神经元（Ia 抑制性中间神经元）参与扰动后姿势反应的产生，该中间神经元使一侧肌肉收缩，而另一侧肌肉放松。这使得流畅的运动和快速的姿势反应成为可能。 在第二个目标中，我们将评估运动皮层在调节站立期间前庭输出中的作用。我们的假设是，皮质部分通过调节前庭系统来控制平衡和姿势反应，形成分层神经元网络来控制平衡。我们进一步假设，当个体站在不稳定的表面上时，运动皮层会更加活跃以保持平衡并防止跌倒。这将增加其影响力。 在第三个目标中，我们将确定来自我们身体（体感）和前庭系统的感觉信息对平衡技能习得过程中肌肉自主激活（运动输出）的影响。我们的假设是，前庭系统和体感系统都有助于在平衡训练期间塑造运动输出，以获得新的平衡技能。 总体而言，拟议的研究计划将进一步加深我们对关键神经元相互作用的了解，从而实现平衡控制和获得平衡技能。它将进一步告诉我们来自我们身体和前庭系统的感觉信息如何被纳入中枢神经系统以实现平衡控制。这项工作在预防日益老龄化的人口中跌倒以及促进需要特殊平衡控制的运动员（例如体操运动员）的不同训练模式方面可能具有潜在的重要应用。这项工作还可能导致技术发展，以支持宇航员在太空探索期间的适应等。