MULTIDIMENSIONAL DYNAMICS OF VESIBULAR-OCULAR REFLEX

由前庭系统产生的补偿性眼球运动是 来自所有半圆形的信息的协调“整合”的结果 运河和耳石 连续性水平眼震的研究 在偏离垂直轴旋转和俯仰头部的过程中产生， 旋转显示了耳石和垂直半规管 可以通过耦合到速度存储器来产生水平眼球震颤 积分器 一个特别惊人的现象，发现在过去的 授权期的一个重要特征是， 在水平和垂直平面的眼球震颤，它是 在重力场的变化下发生了显著的改变 这表明 速度存储可以用更高维的 一个动力学系统，该系统的状态建立一个引力 用于解释头部运动和 视觉环境。 本研究的目的是扩展 视觉-前庭在一个平面上相互作用的前庭眼反射 前庭-眼反射的三维表示， 可以用来解释速度存储在复杂旋转中的作用， 头部 具体来说，我们将确定峰值速度和上升， 眼震后垂直视动下降时间常数 纯水平视动刺激，当动物处于不同的 方向与重力有关。 这将使我们能够获得 水平和垂直耦合的定量估计 速度存储积分器的激励模式。 活动将 细胞外记录从二级垂直以及水平 前庭神经核中的单位。 二阶垂直单位活度 然后将与在偏离垂直轴期间的垂直眼速度进行比较 旋转以确定交叉耦合对垂直眼的影响 位置和眼球震颤。 这项研究应该给出一个数学框架 在其中可以查看head发生的动态转换， 在所有平面上环绕运动。 我们也应该有一个更清晰的概念， 这些参数对于前庭-眼内的交叉耦合是重要的 反射，并有更好的理解的功能意义， 三维速度存储

Compensatory eye movements generated by the vestibular system are the result of a coordinated "integration" of information from all semicircular canals and the otoliths. A study of continuous horizontal nystagmus generated during off vertical axis rotation and pitching the head while rotating has shown how the otoliths and the vertical semicircular canals can generate horizontal nystagmus by coupling to the velocity storage integrator. A particularly striking phenomena discovered during the last grant period is that there is a coupling between storage associated with nystagmus in the horizontal and vertical planes and that it is significantly altered by changes in the gravitational field. This suggests that velocity storage would be represented by a higher dimensional dynamical system with the states of that system establishing a gravity dependent coordinate basis for interpreting head movement and movements of the visual surround. The aim of this research is to extend the model of the vestibulo-ocular reflex for visual-vestibular interaction in one plane to a three dimensional representation of the vestibulo-ocular reflex that can be used to explain the role of velocity storage in complex rotations of the head. Specifically, we will determine the peak velocity and rising and falling time constants of vertical optokinetic after nystagmus following pure horizontal optokinetic stimulation when the animal is in different orientations with regard to gravity. This should enable us to obtain quantitative estimates of the coupling between the horizontal and vertical modes of excitation of the velocity storage integrator. Activity will be recorded extracellularly from second order vertical as well as horizontal units in the vestibular nuclei. The second order vertical unit activity will then be compared to the vertical eye velocity during off-vertical axis rotation to determine what effect cross coupling has on vertical eye position and nystagmus. This research should give a mathematical framework in which to view the dynamic transformations that occur for head and surround movement in all planes. We should also have a clearer idea of the parameters that are important for cross coupling in the vestibulo-ocular reflex and have a better understanding of the functional significance of velocity storage in three dimensions.