Multiplicative computation in the vestibulo-ocular reflex (VOR)

前庭眼反射 (VOR) 的乘法计算

基本信息

批准号：
7596917
负责人：
WU ZHOU
金额：
$ 27.94万
依托单位：
UNIVERSITY OF MISSISSIPPI MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-06-04 至 2012-04-30
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The long-term objective of the application is to understand the neural mechanisms of sensorimotor transformation in the vestibular system. Over the past several decades, the investigation of the VOR has established that the VOR response to a given head movement is not fixed, but is under the modulation of behavioral contexts (i.e., viewing distance). Deficits in the context-dependent VOR gain modulation resulting from disease or environmental changes can severely impair vision. The neural mechanisms underlying this important VOR function, however, remain to be explored. Our recent studies demonstrate that the interaction of vestibular and eye position signals in the direct VOR pathways is multiplicative, rather than additive as presently assumed. Our modeling analysis further suggests a novel neural mechanism that implements the VOR gain modulation by viewing distance. The specific aims of the application are to employ single unit recording and computational modeling approaches to further study the interaction of vestibular and eye position signals in the key components of the direct VOR circuits. A unique strength of the proposal is that we take advantage of the acoustic activation of vestibular system and employ click to evoke impulse responses of the VOR to a unilateral vestibular stimulation. This paradigm permits us examine the neural substrate and signal processing underlying VOR gain modulation. The first aim is to use single unit recording techniques to quantitatively analyze the interaction of vestibular and eye position signals in identified motoneurons that innervate the medial or lateral rectus muscles. These experiments will identify whether the multiplicative computation is performed in the motoneuron pools of the VOR pathway. The second aim is to use single unit recording techniques to quantitatively analyze the interaction of vestibular and eye position signals in three groups of VOR premotor neurons. These experiments will identify whether these VOR interneurons are the sites for multiplicative computation. Computational model simulation will examine the cellular mechanisms underlying the multiplicative interaction in both premotor and motoneurons. This application will provide important knowledge for understanding the fundamental vestibular and oculomotor neurophysiology and improving the diagnosis and treatment of vestibular disorders in humans.

描述（由申请人提供）：申请的长期目标是了解前庭系统中感觉运动转化的神经机制。在过去的几十年中，对VOR的调查已经确定，对给定头部运动的VOR反应不是固定的，而是在行为环境的调节下（即观察距离）。疾病或环境变化引起的上下文依赖性VOR增益调制的缺陷会严重损害视力。然而，该重要VOR功能的基础神经机制仍有待探索。我们最近的研究表明，直接VOR途径中前庭和眼睛位置信号的相互作用是乘法性的，而不是当前假设的添加剂。我们的建模分析进一步提出了一种新型的神经机制，该机制通过查看距离来实现VOR增益调制。该应用程序的具体目的是采用单个单元记录和计算建模方法进一步研究直接VOR电路关键组件中前庭和眼睛位置信号的相互作用。该提案的独特优势是，我们利用前庭系统的声学激活，并采用点击唤起VOR对单侧前庭刺激的冲动反应。该范式允许我们检查VOR增益调制的基础神经底物和信号处理。第一个目的是使用单个单元记录技术来定量分析鉴定运动神经元中内侧或外侧肌肉肌肉的识别运动神经元中的相互作用。这些实验将确定是否在VOR途径的Motoneuron池中执行乘法计算。第二个目的是使用单个单位记录技术来定量分析三组VOR前神经元中前庭和眼睛位置信号的相互作用。这些实验将确定这些VOR中间神经元是否是进行乘法计算的位点。计算模型仿真将检查前结合和运动神经元中乘法相互作用的基础机制。该应用将提供重要的知识，以了解基本的前庭和眼动物神经生理学，并改善人类前庭疾病的诊断和治疗。