MULTIDIMENSIONAL DYNAMICS OF THE VESTIBULO-OCULAR REFLEX

前庭眼反射的多维动力学

• 批准号: 3258647
• 负责人: Theodore Raphan
• 金额: $ 16.4万
• 依托单位: BROOKLYN COLLEGE
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-04-01 至 1994-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3258647
• 关键词: Macaca mulatta; eye movements; gravity; head movements; motion perception; neural information processing; nystagmus; otocyst /otolith; proprioception /kinesthesia; reflex; stimulus /response; vestibular apparatus; vestibular pathway; visceral afferent nerve; visual pathways

Changing the orientation of the head with regard to gravity causes a dramatic change in ocular compensatory movements generated by the visual and vestibular systems. We have recently formulated a three dimensional model of how the central nervous system integrates information from the semicircular canals, visual system and otoliths to explain compensatory eye movements in response to rotations about arbitrary axes in a gravitational environment. We have also shown that gravity has the effect of orienting the principal axes of velocity storage toward the spatial vertical. The aim of this research is to mathematically characterize the velocity storage integrator in three dimensions as a function of gravity to predict these changes in orientation. We also intend to characterize the various dynamical system operators in the model that couple to the velocity storage integrator. Specifically, we will determine the eigenvalues and eigenvectors of the velocity storage integrator for a wide range of orientations of the head with regard to gravity. This will be done by giving oblique optokinetic stimuli for a given position of the head and determining the angle relative to the head where the optokinetic after-nystagmus (OKAN) declines along a straight line in velocity space. This will be the eigenvector. The eigenvalue associated with this eigenvector would be the inverse of the time constant of the decay in OKAN. We will also give off-vertical axis rotation about arbitrary angles through the head to determine the optimal planes for generating compensatory eye velocity in three dimensions. Acitivity will be recorded extracellularly from second order vertical as well as horizontal semicircular canal related units in the vestibular nuclei during and after oblique optokinetic nystagmus and optokinetic after-nystagmus. We propose to determine the role of these units in coding the eigenvectors and eigenvalues of velocity storage and in generating the three components of eye velocity during these type of stimuli. We will also test these units during off-vertical axis rotatation about different axes through the head to determine the optimal planes for estimating head velocity generated by the otoliths. Experimental findings will be related to the three dimensional model of the vestibulo- ocular reflex. This research should give a better understanding of how compensatory eye movements are generated during complex head movements. It should also elucidate the functional role of the velocity storage integrator in generating these movements.

改变头部相对于重力的方向会导致 一个戏剧性的变化，在眼球代偿运动所产生的， 视觉和前庭系统。 我们最近制定了一个三 中枢神经系统如何整合的三维模型 半规管、视觉系统和 耳石来解释补偿性眼球运动， 在引力环境中绕任意轴旋转。 我们 还表明，重力有定向的效果， 速度存储的主轴朝向空间垂直方向。 本研究的目的是从数学上描述 作为函数的三维速度存储积分器 重力来预测这些方向的变化。 我们还打算 描述模型中各种动力系统算子的特征 与速度存储积分器相连 我们特别 将决定速度的本征值和本征向量 用于头的宽范围取向的存储积分器 关于重力。 这将通过给出斜向 针对头部的给定位置的视动刺激，以及 确定相对于头部的角度， 后眼球震颤（OKAN）速度沿沿着直线下降 空间 这将是特征向量。 相关的特征值 与此特征向量将是时间常数的倒数 OKAN的衰退 我们还将给出偏离垂直轴的旋转 通过头部的任意角度来确定最佳的 用于在三个平面中产生补偿眼速度的平面 尺寸. 将从第二次开始在细胞外记录活性 顺序垂直以及水平半规管相关 斜视动时和斜视动后前庭神经核的单位 眼球震颤和视动性后眼球震颤。 我们建议确定 这些单元在编码特征向量和特征值中的作用 速度存储和产生眼睛的三个组成部分 在这种刺激下的速度。 我们还将测试这些 在离垂直轴绕不同轴旋转期间的单位 通过头部来确定用于估计的最佳平面 由耳石产生的头部速度。 实验结果 将与前庭的三维模型相关- 眼反射 这项研究应该能让我们更好地理解 在复杂的头部运动过程中， 动作 它还应阐明联合国系统的职能作用， 速度存储积分器产生这些运动。