Vestibular influences on spatial orientation

描述（由申请人提供）：该项目的长期目标是了解大脑如何使用来自前庭迷路的信息来估计头部的空间方向和运动。具体来说，这些实验将调查来自半规管和重力惯性线索由耳石器官转导的旋转线索之间的在线相互作用。将在恒河猴中测量滚动倾斜心理物理学和眼球运动，同时通过电刺激后管壶腹神经来急性操纵旋转线索。耳道线索将单独呈现（头部处于不同的静态方向，眼睛处于不同的聚散角），并且还将与视觉（视动）和惯性线索相结合。将使用来自主观视觉垂直（SVV）的心理物理任务测量前庭感知，该测试广泛用于评估前庭症状患者。我们假设：1）半规管提供的旋转线索有助于大脑对头部方向的估计，这由半规管激活期间SVV响应的变化证明，这不能通过扭转眼位置的变化来解释;以及2）通过分离相对于头部的重力的实际方向和估计方向，垂直管道的电激活将引起线性加速度的异常估计，通过具有平移前庭眼反射特征的眼球运动来证明。这些实验将有助于阐明来自半规管的旋转信息如何以即时，在线的方式与重力惯性线索相互作用，以产生头部方向和反射性前庭眼球运动的感知估计。这些信息将有助于更好地理解前庭神经系统疾病患者的前庭神经病学机制，包括大多数患者的主要临床表现的突出感知投诉（眩晕）。

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand how the brain uses information from the vestibular labyrinth to estimate the spatial orientation and motion of the head. Specifically, these experiments will investigate the on-line interaction between rotational cues derived from the semicircular canals and gravito-inertial cues transduced by the otolith organs. Roll tilt psychophysics and eye movements will be measured in rhesus monkeys while rotational cues are acutely manipulated by electrical stimulation of the posterior canal ampullary nerves. Canal cues will be presented in isolation (with the head in different static orientations and with the eyes at different vergence angles) and will also be coupled to visual (optokinetic) and inertial cues. Tilt perception will be measured with a psychophysical task derived from the subjective visual vertical (SVV), a test which is widely used to evaluate patients with vestibular symptoms. We hypothesize: 1) that rotational cues provided by the semicircular canals contribute to the brain's estimate of head orientation, evidenced by a shift in SVV responses during canal activation that is not explainable by changes in torsional eye position; and 2) that by dissociating the actual and estimated direction of gravity relative to the head, electrical activation of the vertical canals will induce an aberrant estimate of linear acceleration, evidenced by eye movements with the characteristics of a translational vestibulo-ocular reflex. These experiments will help to elucidate how rotational information derived from the semicircular canals interacts in an immediate, on-line fashion with gravito-inertial cues to produce perceptual estimates of head orientation and reflexive vestibular eye movements. This information will contribute to a better understanding of the mechanisms underlying vestibular symptomatology in patients with labyrinthine and neurologic disorders, including the prominent perceptual complaints (vertigo) that dominate the clinical presentation in most patients.