Neural mechanisms of visual-motor control in smooth pursuit eye movement

摘要 大脑功能是基于神经系统，包括一个长期的循环连接的组合 在许多大脑区域和局部电路中执行每个区域内的特定计算。我们的目标是 了解完整的神经系统如何调节特定的大脑功能。我们解决这个一般性问题 通过研究非人灵长类动物的一种特殊的视觉运动行为：平滑的视觉引导 追踪眼球运动追踪的神经系统包括纹外视区MT、平滑眼 额眼运动区（FEFSEM）、脑桥背外侧核（DLPN）和脑桥背外侧核（DLPN） 脑干中的网状被盖脑桥（NRTP）和小脑的絮状复合体。主要 这个项目的交付是一个神经系统的理解，为顺利追求眼球运动的条款 典型的视觉运动/感觉运动回路的特征。我们的第一个目标是问信号是如何 在MT和FEFSEM之间的皮质-皮质通路中转化。我们将记录多个信号单元 同时在两种结构中改变小块移动点的相关程度， 控制视觉运动信号的可靠性。除了询问信号如何在 两个领域，我们将使用MT和FEFSEM中同时记录的神经元之间的噪声相关性， 限制了它们相互连接的架构。我们的第二个目标是揭示视觉运动的本质 在皮质-桥脑-小脑通路中，MT和FEFSEM转化为 小脑我们将通过记录FEFSEM和絮状物来补充MT和脑桥的现有数据。 复杂的条件下，将完成我们的理解的代表性和处理的视觉- 运动增益和目标速度的期望。我们的第三个目标是探索从絮状神经元到神经元之间的循环联系。 小脑复合体到运动皮层的追踪功能。我们将刺激絮状复合体 在固定和稳态跟踪过程中，同时记录FEFSEM中的神经元。拟议 实验将扩展我们的知识的操作的感觉运动电路的追求，把它放在 一个典型的视觉运动/感觉运动系统的架构的背景下，并揭示什么转换 发生在本地电路中，而不是整个系统的节点之间的远程连接中。

Abstract Brain function is based on neural systems that comprise a combination of long-range recurrent connections among many brain regions and local circuits to perform specific computations within each region. Our goal is to understand how a full neural system mediates specific brain functions. We address this general question through investigation of a specific visual-motor behavior in non-human primates: visual guidance of smooth pursuit eye movements. The neural system for pursuit includes extrastriate visual area MT, the smooth eye movement region of the frontal eye fields (FEFSEM), the dorsolateral pontine nucleus (DLPN) and nucleus reticularis tegmenti pontis (NRTP) in the brainstem, and the floccular complex of the cerebellum. The major deliverable of this project is an understanding of the neural system for smooth pursuit eye movements in terms of the features of a canonical visual-motor/sensory-motor circuit. Our first aim will ask how signals are transformed in the cortico-cortical pathways between MT and FEFSEM. We will record multiple signal units simultaneously in both structures while varying the degree of correlation in small patches of moving dots to control the reliability of visual motion signals. In addition to asking how signals are transformed between the two areas, we will use noise correlations between simultaneously recorded neurons in MT and FEFSEM to constrain the architecture of their interconnections. Our second aim will reveal the nature of the visual-motor transformation in a cortico-ponto-cerebellar pathway from MT and FEFSEM to the floccular complex of the cerebellum. We will complement existing data from MT and the pons by recording in FEFSEM and the floccular complex under conditions that will complete our understanding of the representation and processing of visual- motor gain and expectations of target speed. Our third aim will explore recurrent connections from the floccular complex of the cerebellum to the motor cortex for pursuit, FEFSEM. We will stimulate in the floccular complex during both fixation and steady-state tracking while recording from neurons in FEFSEM. The proposed experiments will extend our knowledge of the operation of the sensory-motor circuit for pursuit, place it in the context of the architecture of a canonical visual-motor/sensory-motor system, and reveal what transformations occur in local circuits versus in long-range connections between nodes of the full system.