Enhancement of multiple components of pursuit eye movement by microstimulation in the arcuate frontal pursuit area in monkeys.
Enhancement of multiple components of pursuit eye movement by microstimulation in the arcuate frontal pursuit area in monkeys.
复制标题
通过微刺激猴子弓形额叶追踪区域增强追踪眼运动的多个组成部分。
DOI：
10.1152/jn.00409.2001
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发表时间：
2002
影响因子：
2.5
通讯作者：
Lisberger,StephenG
中科院分区：
文献类型：
--
作者：
Tanaka,Masaki;Lisberger,StephenG
弓周额叶皮层参与平滑追踪眼运动的控制，但其作用仍不清楚。为了更好地理解“额叶追踪区”（FPA）对追踪的控制，我们在猴子执行各种动眼神经任务时应用了电微刺激。与之前的研究一致，在固定目标固定过程中，由一系列 333 Hz 的 50 μA 脉冲组成的电刺激可在较短的潜伏期（约 26 ms）内引发平滑的眼球运动。当在维持追踪过程中传递刺激脉冲时，引起的平滑眼球运动的大小会增强。这种增强随着持续追踪速度的变化而增加，并且在与某个地点引起的眼球运动的相同方向和相反方向的追踪过程中增强得更大。如果在八个不同方向的追踪过程中传递刺激，则引发的眼速最适合包含两种刺激效果的模型：驱动眼速的方向信号以及在所有方向上持续追踪眼速增益的增加。单独的实验测试了刺激对特定图像运动反应的影响。刺激包括在注视过程中发出的一系列 100 或 200 Hz 的脉冲，因此只能引起小而平滑的眼球运动。如果在微刺激期间固定目标受到短暂干扰，通常较弱的眼动反应会表现出强烈的增强。如果在追踪开始时传递，相同的微刺激会导致眼跳前追踪开始增强，目标速度的步长使目标远离注视位置或沿该部位刺激引起的眼球运动方向移动。 FPA 中的刺激增加了对静止或移动目标的扫视延迟。我们的结果表明，FPA 对追踪系统有两种影响。一个人在一个固定的方向上驱动平滑的眼速，并通过持续的追踪受到在线增益控制。另一种会导致持续追踪的速度和对视觉运动的反应的增强，但对追踪的方向没有强烈的选择性。增强可以在单个站点或多个站点进行。我们得出的结论是，FPA 在追踪的在线增益控制以及可能传递平滑眼球运动方向和速度的命令方面发挥着重要作用。
Periarcuate frontal cortex is involved in the control of smooth pursuit eye movements, but its role remains unclear. To better understand the control of pursuit by the “frontal pursuit area” (FPA), we applied electrical microstimulation when the monkeys were performing a variety of oculomotor tasks. In agreement with previous studies, electrical stimulation consisting of a train of 50-μA pulses at 333 Hz during fixation of a stationary target elicited smooth eye movements with a short latency (∼26 ms). The size of the elicited smooth eye movements was enhanced when the stimulation pulses were delivered during the maintenance of pursuit. The enhancement increased as a function of ongoing pursuit speed and was greater during pursuit in the same versus opposite direction of the eye movements evoked at a site. If stimulation was delivered during pursuit in eight different directions, the elicited eye velocity was fit best by a model incorporating two stimulation effects: a directional signal that drives eye velocity and an increase in the gain of ongoing pursuit eye speed in all directions. Separate experiments tested the effect of stimulation on the response to specific image motions. Stimulation consisted of a train of pulses at 100 or 200 Hz delivered during fixation so that only small smooth eye movements were elicited. If the stationary target was perturbed briefly during microstimulation, normally weak eye movement responses showed strong enhancement. If delivered at the initiation of pursuit, the same microstimulation caused enhancement of the presaccadic initiation of pursuit for steps of target velocity that moved the target either away from the position of fixation or in the direction of the eye movement caused by stimulation at the site. Stimulation in the FPA increased the latency of saccades to stationary or moving targets. Our results show that the FPA has two kinds of effects on the pursuit system. One drives smooth eye velocity in a fixed direction and is subject to on-line gain control by ongoing pursuit. The other causes enhancement of both the speed of ongoing pursuit and the responses to visual motion in a way that is not strongly selective for the direction of pursuit. Enhancement may operate either at a single site or at multiple sites. We conclude that the FPA plays an important role in on-line gain control for pursuit as well as possibly delivering commands for the direction and speed of smooth eye motion.