Departments of Biomedical Engineering, of Otolaryngology-Head and Neck Surgery, and of Neuroscience; Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD, United States.
Handb Clin Neurol. 2023;195:31-54. doi: 10.1016/B978-0-323-98818-6.00022-4.
The vestibular system is an essential sensory system that generates motor reflexes that are crucial for our daily activities, including stabilizing the visual axis of gaze and maintaining head and body posture. In addition, the vestibular system provides us with our sense of movement and orientation relative to space and serves a vital role in ensuring accurate voluntary behaviors. Neurophysiological studies have provided fundamental insights into the functional circuitry of vestibular motor pathways. A unique feature of the vestibular system compared to other sensory systems is that the same central neurons that receive direct input from the afferents of the vestibular component of the 8th nerve can also directly project to motor centers that control vital vestibular motor reflexes. In turn, these reflexes ensure stabilize gaze and the maintenance of posture during everyday activities. For instance, a direct three-neuron pathway mediates the vestibulo-ocular reflex (VOR) pathway to provide stable gaze. Furthermore, recent studies have advanced our understanding of the computations performed by the cerebellum and cortex required for motor learning, compensation, and voluntary movement and navigation. Together, these findings have provided new insights into how the brain ensures accurate self-movement during our everyday activities and have also advanced our knowledge of the neurobiological mechanisms underlying disorders of vestibular processing.
前庭系统是一个重要的感觉系统，它产生的运动反射对于我们的日常活动至关重要，包括稳定注视的视觉轴和维持头部和身体的姿势。此外，前庭系统为我们提供了运动感和相对于空间的方向感，在确保准确的自主行为方面起着至关重要的作用。神经生理学研究为前庭运动通路的功能回路提供了基本的见解。与其他感觉系统相比，前庭系统的一个独特特征是，同一中枢神经元既可以直接接收来自第 8 神经前庭成分传入的输入，也可以直接投射到控制重要前庭运动反射的运动中枢。反过来，这些反射确保在日常活动中稳定注视和维持姿势。例如，一个直接的三神经元通路介导了前庭眼反射（VOR）通路，以提供稳定的注视。此外，最近的研究提高了我们对小脑和皮层进行运动学习、补偿和自主运动及导航所需的计算的理解。这些发现共同为大脑如何在日常活动中确保准确的自我运动提供了新的见解，并提高了我们对前庭处理障碍的神经生物学机制的认识。
