CORTICAL CONTRIBUTIONS TO CONTROL OF EYE MOVEMENTS

皮质对眼球运动控制的贡献

• 批准号: 2162097
• 负责人: MARK A SEGRAVES
• 金额: $ 15.63万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-08-01 至 1998-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2162097
• 关键词: Macaca mulatta; bicuculline; brain electrical activity; cerebral cortex; electrophysiology; eye movements; muscimol; neural information processing; neuroanatomy; neurophysiology; oculomotor nuclei; pons; saccades; superior colliculus; visual fields; visual fixation; visual pathways; visual stimulus

The long-term goal of this laboratory is to understand the contributions made by the primate's cerebral cortex to the control of motor behavior. Experiments are focused on the role of the rhesus monkey's frontal and supplementary eye fields (FEF & SEF) in the generation of eye movements. These areas have been identified in both human and non-human primates and appear to be particularly important for eye movements that are driven by cognitive processes, for example, when a saccade is made to a remembered location or for the patterns of eye movements generated during reading The FEF and SEF have a number of features in common: they both contain neurons whose firing is related to the generation of saccades, and they both project to the superior colliculus and to oculomotor regions of the pons. There are also notable differences. Studies suggest that the FEF is more closely tied to sensory-motor processes, and is concerned with the generation of the next saccade. The SEF may be situated at a slightly higher level, and is involved in the planning of sequences of several saccades. This project is designed to expand our knowledge about the respective roles of the FEF and SEF in the control of saccades by identifying the types and effects of signals these two areas send to oculomotor regions in the brainstem, and by comparing the contributions of these two areas to the generation of natural scanning eye movements. The project has two components. The first examines the activity of identified SEF cells that project to the superior colliculus or to oculomotor regions of the pons. This will be done by antidromically exciting SEF neurons from the brainstem, and will identify signals sent by the SEF to pontine and collicular oculomotor centers. In addition, the effects of inputs from the FEF and SEF to superior colliculus and pons will be examined using orthodromic stimulation of cortex while recording from brainstem neurons, and by cross-correlation analysis of simultaneous recordings made from cortex and brainstem. The second component employs a new behavioral paradigm to evoke natural scanning eye movements. In this paradigm, eye movements and neural activity are recorded while a monkey freely views projected visual images. FEF and SEF eye activity during this paradigm will be compared to the activity occurring during conventional visuomotor tasks. The importance of these two areas for the generation of eye movements in this paradigm will be examined by artificially increasing or decreasing activity in a localized region by injection of the GABA antagonist bicuculline or agonist muscimol, or by inactivating a localized region with a microinjection of lidocaine. Together, these experiments will further our understanding of the role of these regions of frontal cortex in the control of eye movements, and will aid in the understanding of the differences between the FEF and SEF in their roles in the control of eye movements. The brains of rhesus monkeys and humans are similar, and the principles of function and organization revealed by these experiments are likely to apply to humans.

该实验室的长期目标是了解贡献 由灵长类动物的脑皮质制成，以控制运动行为。 实验的重点是恒河猴的额叶和 在眼动动作中的补充眼场（FEF和SEF）。 这些领域已在人类和非人类灵长类动物中都被发现 对于由驱动的眼睛运动尤其重要 例如，当对被记住的扫视时，认知过程 位置或在阅读过程中产生的眼睛运动的模式 FEF和SEF具有许多共同的特征：它们都包含神经元 其射击与扫视的一代有关，他们俩 投影到上丘和PON的动眼球区域。 也有显着的差异。研究表明FEF更多 与感觉运动过程紧密相关，并关注 下一个扫视的产生。 SEF可能位于 较高的水平，并参与了几个序列的规划 扫视。该项目旨在扩大我们对 FEF和SEF各自在控制扫视中的角色 确定信号的类型和效果这两个区域发送到 通过比较 这两个区域是自然扫描眼动的产生。这 项目有两个组件。第一个检查确定的活动 投射到上丘或眼动物区域的SEF单元 pons。这将由来自抗粒度令人兴奋的SEF神经元的 脑干，并将确定SEF发送给Pontine的信号和 胶体动力学中心。另外，输入的影响 将使用FEF和SEF到上丘和PON 从脑干神经元记录时皮质的正质刺激， 并通过对由 皮层和脑干。第二部分采用新的行为 范式唤起自然扫描眼动。在这个范式中，眼睛 记录动作和神经活动，而猴子自由观看 投影的视觉图像。 FEF和SEF眼活动在此范式中 将比较常规视觉运动期间发生的活动 任务。这两个领域对于生成眼睛的重要性 该范式中的运动将通过人为增加或 通过注入GABA，在局部区域减少活性 拮抗者双瓜氨酸或激动剂麝香酚，或通过灭活局部 带有利多卡因的区域。在一起，这些实验 将进一步理解这些额叶地区的作用 在控制眼动的皮质中，将有助于理解 FEF和SEF在控制中的角色中的差异 眼动。恒河猴和人类的大脑相似，并且 这些实验揭示的功能和组织原理 可能适用于人类。