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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=764475
• 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保持平衡，因为人行道就像一个巨大的溜冰场，而仅仅走到街角就像一个艺术滑冰程序。因此，平衡控制是我们日常生活中必不可少的一部分，但使这些行为成为可能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神经元相互作用的性质，使人类的平衡控制。 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，但其作用的实际机制在很大程度上是未知的。我提议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。 在第一个目标中，我们将评估前庭系统对位于脊髓中的神经元的影响，在意外向后倾斜的基础上的支持。我们的假设是，前庭系统通过促进脊髓中特定的中间神经元（Ia抑制性中间神经元）参与扰动后姿势反应的产生，该中间神经元使一个肌肉收缩，而另一个肌肉放松。这使得流体运动和快速的姿势反应。在第二个目标，我们将评估的作用，运动皮层在调节前庭输出在站立。我们的假设是，大脑皮层控制平衡和姿势反应的一部分是通过调节前庭系统，形成一个层次神经网络来控制平衡。我们进一步假设，当个体站在不稳定的表面上时，运动皮层将更加活跃，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的感觉信息（躯体感觉）和前庭系统对平衡技能获得期间我们肌肉的自愿激活（运动输出）的影响。我们的假设是，前庭和躯体感觉系统都有助于在平衡训练中形成运动输出，以获得新的平衡技能。 总的来说，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，这些神经元相互作用使平衡控制和获得平衡技能成为可能。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。这项工作可能在防止日益老龄化的人口中的福尔斯跌倒方面具有潜在的重要应用，并促进需要特殊平衡控制的运动员（例如体操运动员）的不同训练范式。这项工作还可能导致技术发展，例如在空间探索期间支持宇航员的适应。