Neural Control of Visually Guided Eye Movements

描述（由申请人提供）：拟议研究的目的是确定灵长类动物的三个皮层区域如何有助于产生视觉引导的扫视眼球运动：额叶眼野、内侧眼野和外侧顶内沟。我们提出的实验旨在评估：（1）来自皮层的信号如何到达脑干视神经中枢，（2）这三个区域的兴奋性和抑制性回路如何调节眼动控制，以及（3）这三个区域在多大程度上也参与了眼/手的协调。 三组实验计划：实验1将确定是否在完整的动物扫视眼球运动的产生是通过两个平行的通道，前和后，我们已经假设在我们早期的长期病变研究。为了确定这两个通路在完整动物中是否有功能，将使用上级丘的短期单侧和双侧可逆失活来研究额眼野和内侧眼野的电刺激的影响。 实验2将评估在眼动控制中，额叶眼野、内侧眼野和外侧顶内沟的兴奋性和抑制性神经元回路所起的作用。为了实现这一点，将在一系列行为任务中研究眼球运动的产生，当这些区域被注入谷氨酸和GABA的短暂作用的激动剂和拮抗剂时。实验3将确定这三个区域在多大程度上有助于眼/手的协调，除了扫视眼动的产生。将在可逆性阻滞剂局部输注之前、期间和之后评估眼/手协调任务的表现。 从拟议的实验中获得的结果应该有显着的影响，眼运动障碍的治疗。如果在完整的生物体中，前、后两条神经流（正如我们在早期工作中所提出的那样）确实具有功能性（正如本系列的第一组实验所确定的那样），那么就可以设计出比所有大脑皮层指令都通过上级丘来移动眼睛更有效的治疗程序。

DESCRIPTION (provided by applicant): The aim of the proposed research is to determine how three cortical areas in the primate contribute to the generation of visually guided saccadic eye movements: the frontal eye fields, the medial eye fields and the lateral intraparietal sulcus. The experiments we propose are designed to assess: (1) How the signals from the cortex reach the brainstem oculomotor centers, (2) how excitatory and inhibitory circuits in these three areas mediate eye-movement control, and (3) the extent to which the three areas are also involved in eye/hand coordination. Three sets of experiments are planned: Experiment 1 will determine whether in the intact animal saccadic eye-movement generation is achieved through two parallel channels, the anterior and the posterior, as we had hypothesized in our earlier long-term lesion studies. To determine whether these two pathways are functional in the intact animal, the effects of electrical stimulation of the frontal eye fields and medial eye fields will be studied using short-term unilateral and bilateral reversible inactivation of the superior colliculus. Experiment 2 will assess the role excitatory and inhibitory neuronal circuits play in the frontal eye fields, the medial eye fields and the lateral intraparietal sulcus in eye movement control. To accomplish this, the generation of eye movements will be studied in a series of behavioral tasks when these areas are infused with briefly acting agonists and antagonists of glutamate and GABA. Experiment 3 will determine the extent to which these three areas contribute to eye/hand coordination in addition to saccadic eye-movement generation. Performance on eye/hand coordination tasks will be assessed before, during and after local infusions of reversible blocking agents. The results obtained from the proposed experiments should have significant implications for the treatment of eye-movement disorders. If in the intact organism the anterior and posterior streams, as had been proposed in our earlier work, are indeed functional, as to be determined in the first set of experiments in this series, more effective treatment routines can be devised than if all cortical commands to move the eyes traverse through the superior colliculus.