Investigating the functional role of sensory receptors in human movement and postural control

作为人类，我们使用视觉和前庭(内耳)信息，以及肌肉和皮肤传感器的输入来保持平衡。我的研究计划的长期目标是了解生理机制，使来自皮肤、肌肉和前庭系统的信息能够调节正在进行的任务，并在站立和行走时产生适当的姿势反应。我的近期目标是研究站立时皮肤和前庭信息有助于保持平衡的机制。来自足底皮肤的信息已被证明对姿势稳定有作用。这可以通过麻醉或脚底降温来增加摆动来证明。足底有不同类型的感觉感受器；它们已经被证明可以改变腿部的肌肉活动。这一观察表明，来自皮肤的运动连接用于控制下肢的运动，或许还包括平衡控制。通过使用显微神经学的新技术，其中记录是由人类的单个传入神经纤维制成的，我们可以分离出不同类型的皮肤传入。将摇摆的变化与单个受体的激活联系起来，将使我们能够测试皮肤中对保持稳定性重要的信息类型。虽然来自前庭系统的输入也被证明可以改变腿部的肌肉活动，但人们对皮肤和前庭输入如何整合以控制平衡知之甚少。我的工作将测试前庭输入如何与来自脊髓水平的独立足底皮肤感受器的信息相互作用。这项工作是了解皮肤和前庭参与平衡背后的机制的基础，也是朝着长期解决皮肤输入缺陷(如糖尿病神经病变、年龄)的第一步。了解特定受体的作用，以及它们与前庭输入的相互作用，最终将有助于简化康复策略，并提高我们帮助有活动能力和平衡缺陷的人的能力。

As humans, we use visual and vestibular (inner ear) information, as well as input from sensors in muscles and skin, to maintain balance. The long term objective of my research program is to understand the physiological mechanisms which enable information from the skin, muscles and vestibular system to modulate ongoing tasks and generate appropriate postural responses during standing and walking. My immediate goal is to investigate the mechanisms by which skin and vestibular information are able to contribute to balance during standing. Information from skin on the foot sole has been shown to have a role in postural stability. This can be demonstrated by an increase in sway with either anaesthesia or through cooling of the foot soles. There are different types of sensory receptors in the foot sole; they have been shown to alter muscle activity in the leg. This observation suggests a motor connection from skin for the control of lower limb movement, and perhaps balance control. By using the novel technique of microneurography, where recordings are made from single afferent nerve fibres in the human, we can isolate individual types of skin afferents. Correlating changes in sway to the activation of individual receptors will enable us to test the type of information from the skin that is important to maintain stability. Although input from the vestibular system has also been shown to change muscle activity in the legs, it is poorly understood how skin and vestibular input are integrated to control balance. My work will test how vestibular inputs interact with information from independent foot sole cutaneous receptors at the level of the spinal cord. This work is fundamental to understanding the mechanisms behind the cutaneous and vestibular involvement in balance and is a first step towards long term solutions for deficits in cutaneous input (such as diabetic neuropathy, age). Knowledge of the contributions from specific receptors, and their interaction with vestibular input will ultimately help streamline rehabilitative strategies and lead to improvements in our ability to aid individuals with mobility and balance deficits.