Vestibular Compensation During Volitional Head Movements

描述(申请人提供)：本项目的目的是为了澄清 前庭损伤后恢复的机制(前庭 在灵长类动物中)。实验将集中在生理学方面。 前庭-眼反射(VOR)恢复的潜在过程 单侧迷路切除或半规管堵塞。初步 研究调查了意志在代偿性眼球中所起的作用。 分析自由眼球和头部跳动时头部运动时的反应 迷路损伤前后的运动(无头注视移位)。这些 研究表明，猴子能够利用神经传出的副本 编码头部运动和/或颈部或视觉反馈的信号 在自然、不受约束的头部运动中促进行为补偿。 对前庭核团神经元的单位记录正在进行中 分析他们眼球运动和被动角加速度敏感度的变化 单侧迷路损毁前及代偿后。假设是为了 在目前的研究中被测试的是神经信号的传出副本 在这些头部运动期间使用编码意志性头部运动来 改变中央前庭神经元的反应，促进 代偿动物凝视的稳定性。这一假设将通过以下方式检验 记录已识别的中央前庭神经元在两种被动状态下的反应 全身旋转和头部水平不受限制的凝视任务。其效果 将根据来自磁头的输入来解释磁头停顿 加速度计，它与所有其他记录和记录的 控制信号。这项研究的预期收益将是可能的 在神经元水平显示传出复制。这项研究是一项 候选人对前庭补偿的兴趣的发展，这 从他以前的研究经验和他作为一名 耳鼻喉科医生治疗主诉头晕的病人。这项工作是一项 P.I.S持续职业发展奖的延续和补充 项目(K-08-DC00182)。

DESCRIPTION (provided by applicant): The purpose of this project is to elucidate the mechanisms involved in recovery from vestibular injury (vestibular compensation) in primates. Experiments will focus on the physiological processes underlying recovery of the vestibulo-ocular reflex (VOR) following unilateral labyrinthectomy or plugging of the semicircular canals. Preliminary studies have investigated the role played by volition in compensatory ocular responses during head movement by analyzing unrestrained eye and head saccadic movements (head-free gaze shifts) before and after labyrinthine lesion. These studies demonstrated that a monkey is able to utilize efference copies of neural signals that encode head movements and/or cervical or visual feedback to facilitate behavioral compensation during natural, unrestrained head movements. Single-unit recordings of neurons in the vestibular nuclei are underway to analyze changes in their oculomotor and passive angular acceleration sensitivity before unilateral labyrinthine lesion and after compensation. The hypothesis to be tested in the current study is that efference copies of neural signals encoding volitional head movements are used during those head movements to modify the response of central vestibular neurons, facilitating the stabilization of gaze in compensated animals. This hypothesis will be tested by recording responses of identified central vestibular neurons during both passive whole body rotation and horizontally head unrestrained gaze tasks. The effect of head stoppage will be interpreted in light of the input from the head accelerometer, which is recorded along with all of the other recorded and control signals. A desired benefit of this research will be the possible demonstration of efference copy at the neuronal level. This research is an outgrowth of the candidate's interest in vestibular compensation, which developed from his previous research experience and from his work as an otolaryngologist treating patients complaining of dizziness. This work is an extension and supplementation of the P.I.'s ongoing career development award project (K-08-DC00182).