VESTIBULOOCULAR REFLEX AND ITS INTERACTIONS WITH VISUAL FOLLOWING MECHANISMS IN THE SQUIRREL-MONKEY .1. RESPONSE CHARACTERISTICS IN NORMAL ANIMALS
VESTIBULOOCULAR REFLEX AND ITS INTERACTIONS WITH VISUAL FOLLOWING MECHANISMS IN THE SQUIRREL-MONKEY .1. RESPONSE CHARACTERISTICS IN NORMAL ANIMALS
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DOI：
10.1152/jn.1983.49.1.134
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发表时间：
1983-01-01
影响因子：
2.5
通讯作者：
PAIGE, GD
中科院分区：
文献类型：
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作者：
PAIGE, GD
本文对8只松鼠猴的水平前庭眼反射（VOR）、水平视动跟随（OK）及其相互作用进行了研究。在0.01-4.0 Hz的频率范围内，以恒定的峰值速度呈现动物和/或OK鼓的正弦旋转。慢相眼球运动的增益和相位相对于头部或鼓的旋转进行了分析。VOR增益相对平坦，平均值为0.86 ± 0.95。0.03在整个频率带宽上。相位超前接近0 °。从4.0到0.1Hz，在较低频率上升到40.3 °。0.01 Hz。后一阶段是一致的有效的一阶时间常数为19秒。VOR的动态范围通过在40- 360 °/s范围内改变峰值头速度来评估。0.2和0.02 Hz时的s。VOR在0.2 Hz处表现为线性，增益和相位在头部速度增加9倍时几乎保持恒定。相比之下，振幅相关的非线性在0.02 Hz处是明显的。在高强度正弦旋转期间，在VOR中可以看到聚散分量，并且可以帮助在双目目标固定期间保持视觉图像稳定。还研究了VOR对角加速度阶跃变化的响应。估计的增益和时间常数接近从正弦响应确定的那些。在阶跃反应中观察到的适应表现为过加速反应下降和后加速二级反应。在正弦响应中，自适应表现为低于0.1 Hz的相位超前比一阶动力学预测的更陡的上升。将VOR与已知的周围神经管传入特性进行比较，发现有效神经管传入表明VOR的有效带宽被扩展到比其传入输入更低的频率; VOR不反映在频率> 1Hz的传入反应中看到的相位超前和增益增强，在VOR中观察到的适应现象类似于在传入反应中描述的类似过程。对正弦和恒速滚筒旋转的OK响应进行了评估。结果是一致的概念，OK以下反映了一个相对较快的中央凹的追求系统和较慢的视觉以下系统的组合，大概涉及周边视野。OK后眼球震颤（OKAN），在30 s的等速OK鼓旋转后熄灭灯光时观察到，以平均19 s的时间常数衰减。在存在固定OK鼓的情况下动物旋转期间（视觉增强）以及动物和OK鼓串联旋转期间（视觉抑制），评估视觉-前庭相互作用。在增强或抑制期间获得的眼球运动与VOR和OK响应的线性总和一致。从罗宾逊（1977）修改的模型模拟了对单独和组合的前庭和OK刺激的反应。
The horizontal vestibuloocular reflex (VOR), horizontal optokinetic (OK) following, and their interactions were studied in 8 squirrel monkeys. Sinusoidal rotations of the animal and/or an OK drum were presented in the frequency range 0.01-4.0 Hz at constant peak velocity. Slow-phase eye movements were analyzed in terms of their gains and phases relative to rotation of the head or drum. VOR gain is relatively flat, averaging 0.86 .+-. 0.03 over the entire frequency bandwidth. Phase lead is near 0.degree. from 4.0 to 0.1 Hz, rising at lower frequencies to reach 40.3.degree. at 0.01 Hz. The latter phase is consistent with an effective first-order time constant of 19 s. The dynamic range of the VOR was assessed by varying peak head velocity over the range 40-360.degree./s at 0.2 and at 0.02 Hz. The VOR behaves linearly at 0.2 Hz, gain and phase remain nearly constant over a 9-fold increase in head velocity. In contrast, amplitude-dependent nonlinearities are apparent at 0.02 Hz. A vergence component is seen in the VOR during high-intensity sinusoidal rotations and may help to maintain visual image stabilization during binocular target fixation. The VOR was also studied in response to step changes in angular acceleration. Estimated gain and time constant are close to those determined from sinusoidal responses. Adaptation is observed in step responses as a peracceleratory response decline and a postacceleratory secondary response. In sinusoidal responses, adaptation is manifested as a steeper rise in phase lead below 0.1 Hz than 1st-order dynamics would predict. Comparison of the VOR with known characteristics of peripheral canal afferents indicates that the effective canal afferents indicates that the effective bandwidth of the VOR is extended to lower frequency than that of its afferent input; the VOR does not reflect the phase lead and gain enhancement seen in afferent responses at frequencies > 1 Hz, and the adaptation phenomenon observed in the VOR resembles a similar process described in afferent responses. OK responses to sinusoidal and constant-velocity drum rotations were assessed. Results are consistent with the notion that OK following reflects a combination of a relatively fast foveal pursuit system and a slower visual following system, presumably involving the peripheral visual field. OK afternystagmus (OKAN), observed on extinguishing the light after 30 s of constant-velocity OK drum rotation, decays with a time constant averaging 19 s. Visual-vestibular interactions were assessed during rotation of the animal in the presence of a stationary OK drum (visual enhancement) and during rotation of the animal and the OK drum in tandem (visual suppression). The eye movements obtained during either enhancement or suppression are consistent with a linear summation of VOR and OK responses. A model, modified from Robinson (1977), simulates the responses to separate and combined vestibular and OK stimulation.