VESTIBULAR NUCLEUS ACTIVITY IN VESTIBULAR COMPENSATION

本项目的目的是阐明灵长类动物前庭损伤（前庭补偿）恢复的机制。 实验将集中在生理过程中恢复前庭眼反射（VOR）后，单侧椎板切除术或半规管堵塞。 将通过分析视网膜病变前后无限制的眼睛和头部扫视运动（无头部凝视转移），研究意志在头部运动期间代偿性眼反应中所起的作用。 将分析前庭核神经元的单单位记录，以了解单侧前庭神经损伤前和代偿后其眼动和角加速度敏感性的变化。 本研究假设：（1）前庭-眼反应中的被动前庭代偿是双侧前庭核团间连合连接可塑性的结果，（2）前庭核团中的神经元具有与正常动物相同的眼敏感性;以及（3）动物能够利用编码头部运动和/或颈部反馈的神经信号的传出副本，以促进在自然的、不受限制的头部运动期间的行为补偿。 这项研究是候选人对前庭补偿感兴趣的结果，这是从他以前的研究经验和他作为耳鼻喉科医生治疗头晕患者的工作中发展起来的。 本提案中的工作将在W.迈克尔·金与密西西比大学医学中心研究前庭和眼功能的各种研究人员合作。 为了补充实验室的工作，候选人将接受计算机功能和编程和生物统计学的指导，以促进候选人作为研究前庭系统可塑性的独立调查员/临床医生的建立，特别是因为它涉及到自然的头部运动。

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. The role played by volition in compensatory ocular responses during head movement will be investigated by analyzing unrestrained eye and head saccadic movements (head-free gaze shifts) before and after labyrinthine lesion. Single-unit recordings of neurons in the vestibular nuclei will be analyzed for changes in their oculomotor and angular acceleration sensitivity before unilateral labyrinthine lesion and after compensation. The hypotheses to be tested are that (1) passive vestibular compensation seen in vestibulo-ocular responses is the result of plasticity in the commissural connections between the bilateral vestibular nuclei; (2) the neurons found in the vestibular nuclei of the compensated animal carry the same oculomotor sensitivity as in the intact animal; and (3) the animal is able to utilize efference copies of neural signals which encode head movements and/or cervical feedback to facilitate behavioral compensation during natural, unrestrained head movements. 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. The work in this proposal will be done under the direction of Dr. W. Michael King in collaboration with a diverse group of investigators who study vestibular and oculomotor function at the University of Mississippi Medical Center. To complement the work in the lab, the candidate will undergo instruction in computer function and programming and biostatistics to facilitate establishment of the candidate as an independent investigator/clinician studying plasticity in the vestibular system, particularly as it pertains to natural head movements.