Neural mechanisms of 3-D linear vestibuloocular reflex

3-D 线性前庭眼反射的神经机制

• 批准号: 7059901
• 负责人: CHIJU C CHEN-HUANG
• 金额: $ 24.9万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7059901
• 关键词: Saimiri; antidromic impulse; electrodes; electrostimulus; evoked potentials; head movements; interneurons; motor neurons; neural information processing; neural plasticity; oculomotor nuclei; smooth pursuit eye movement; synapses; vestibuloocular reflex; visual fixation

DESCRIPTION (provided by applicant): Among the sensory modalities available to vertebrate animals, vision is most advantageous for it provides information in a wide three dimensional space with high acuity. Thus, redirecting our eyes to retain images of objects of interest on the fovea while we are in motion becomes a crucial motor function. The nervous system solves this problem by using short-latency vestibulo-ocular reflexes (VORs) to generate eye movements that compensate for angular (angular VOR or AVOR) or linear (linear VOR or LVOR) motions of the head. Sensory inputs driving the AVOR and LVOR arise from different labyrinthine sensors (the semicircular canals and otolith organs, respectively). This means that, if as existing evidence suggests, the compensatory LVOR is built upon the phylogenetically older AVOR brainstem circuitry and thus both share a common premotor pathway, the linear acceleration signals coded by otolith afferents must be transformed to match the velocity-position signals generally observed on AVOR neurons. Likewise, the three-dimensional spatial directions of angular and linear motion signals must be brought into alignment. Complexity arises since different patterns of eye movements are evoked in response to high frequency linear motions, which generate translational LVORs, and to low frequency linear motions, which generate orienting (tilt) responses. Alternatively, AVOR, LVOR and tilt-related signals might be carried via separate VOR pathways converging upon extraocular motoneurons. Another unresolved issue is that the bilateral organization of otolith and canal sensory epithelia is quite different, and thus the bilateral "push-pull" mechanism in AVOR may not apply to LVOR. The four aims that follow are designed to address these and other related questions regarding coordinated VOR responses to angular and linear head motions. These aims are: Identify the synaptic connections of VOR neurons that project to oculomotor nuclei and receive direct VIIIth nerve inputs. Examine the spatial and temporal tuning properties of VORns during the AVOR, LVOR, smooth pursuit and fixation of targets at various viewing distances. Examine the bilateral organization of utriculus related inputs to VOR neurons. Examine responses of VORns during static tilts and low frequency earth-horizontal rotations that produce comparable acceleration to translations and examine how translation and tilt related signals are distributed in VOR pathways.

描述（由申请人提供）：在脊椎动物可用的感官方式中，视觉最有利，因为它在敏锐度高的三维空间中提供了信息。因此，将眼睛重定向以在我们进行运动时保留中央凹对象的图像成为至关重要的运动功能。神经系统通过使用短期前圆形骨反射（VOR）来解决此问题，从而产生眼睛运动，以补偿头部的角度（角VOR或AVOR）或线性（线性VOR或LVOR）运动。感觉输入驱动AVOR和LVOR是由不同的迷宫传感器（分别是半圆形管和耳石器官）产生的。这意味着，如现有证据所表明的那样，代偿性LVOR建立在系统发育较老的avor脑干电路上，因此两者都具有共同的前途径，则必须转换由耳石传入的线性加速度信号，以匹配速度位置信号，通常在Avor神经元上观察到速度位置信号。同样，必须将角性运动信号和线性运动信号的三维空间方向放在对齐中。复杂性之所以出现，是因为眼睛运动的不同模式是响应高频线性运动而产生翻译LVOR和低频线性运动的高频线性运动的，从而产生方向（倾斜）响应。另外，可以通过分离眼外运动神经元的单独的VOR途径来携带Avor，LVOR和倾斜相关信号。另一个尚未解决的问题是耳石和运河感觉上皮的双边组织截然不同，因此，Avor中的双边“推力”机制可能不适用于LVOR。接下来的四个目标旨在解决有关角度和线性头运动的协调VOR响应的这些和其他相关问题。这些目标是： 确定向动眼核投射的VOR神经元的突触连接并接收直接的Viiith神经输入。 在各种观看距离处检查伏恩，LVOR，平滑追捕和目标的伏族人的空间和时间调谐特性。 检查与神经元相关输入的双边组织。检查在静态倾斜和低频地球 - 旋转旋转过程中的vorn响应，这些旋转产生与翻译的可比加速度，并检查如何在VOR途径中分布翻译和相关信号。