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

摘要 大脑的功能是建立在神经系统的基础上的，这些神经系统组成了一组长距离的经常性连接 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 以了解完整的神经系统如何调节特定的大脑功能。我们解决了这个一般性问题 通过对非人灵长类动物一种特殊的视觉运动行为的研究：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，平滑的眼睛 额眼运动区(FEFSEM)、桥脑背外侧核(DLPN)和核团 脑干的被盖网状脑桥(NRTP)和小脑的小叶复合体。少校 这个项目的交付内容是对神经系统顺畅追踪眼球运动的理解 典型的视觉-运动/感觉-运动电路的特征。我们的首要目标是询问信号如何 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 同时在两种结构中同时改变移动点的小斑块中的相关程度以 控制视觉运动信号的可靠性。除了询问信号是如何在 我们将利用MT和FEFSEM中同时记录的神经元之间的噪声相关性来 限制其互连的架构。我们的第二个目标将揭示视觉运动的本质 皮质-桥脑-小脑通路从MT和FEFSEM向大脑皮质-桥脑-小脑纤维复合体的转化 小脑。我们将补充现有的来自MT和脑桥的数据，记录在FEFSEM和FLOCLECT上 复杂的条件下，将完成我们对视觉的表征和处理的理解-- 马达增益和目标速度的预期。我们的第三个目标是探索来自小球的反复连接。 小脑到运动皮质的复合体进行追踪，FEFSEM。我们将在絮状复合体中刺激 在注视和稳态跟踪期间，同时记录FEFSEM中的神经元。建议数 实验将扩展我们对用于追逐的感觉-运动电路的操作的知识，将其放置在 规范的视觉-运动/感觉-运动系统的体系结构的背景，并揭示了 发生在本地电路中，而不是在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.