Optogenetic dissection of inter-hemispheric frontal eye field circuits for eye movements

摘要 视觉运动转换和眼球运动的产生需要这样的处理， 同时发生在两个大脑半球人们常常认为， 信息从一个半球转移到另一个半球， 移动计划是微不足道的问题。然而，这是不可能的情况下，因为许多视觉运动 疾病与半球间交流功能障碍有关，包括 斜视、弱视、忽视和癫痫。因此，大脑半球间的交流是一种 研究不足但却是大脑功能的核心部分。 能够同时从两个半球记录并识别准确的神经元 它们之间的连接传统上很难实现。然而，我们最近 开发了光遗传学工具，可以可靠地定位和标记跨半球输入， 特定的大脑区域。再加上记录神经元群体的现代技术， 这种方法有望开创一个以灵长类动物为中心的研究新时代， 需要联合收割机在两个半球的皮层活动，以产生明确的 接受并计划一个具体的行动。 直接连接大脑半球之间的神经元连接与其功能的能力 在视觉运动行为中的作用为研究长期存在的 一个半球中特定运动矢量的活动抑制不同的运动矢量的假说 另一种是运动。我们提出实验，测试这一假设，资本化 在良好的特点，精确测量，和自然的性质，眼球运动， 他们的大脑皮层控制的额叶眼场（FEF）。在我们的第一个具体目标，我们将光学 识别并激活一个FEF中的神经元，这些神经元在记录时投射到整个半球 从受体神经元在其他FEF，以确定是否增加活动在一个 大脑半球降低受体神经元的活动与不同的方向偏好， 另一半我们的第二个具体目标将使用类似的设置，但抑制活性 跨半球皮层输入，以更彻底地测试控制大脑的网络结构。 大脑半球间的交流总的来说，拟议的实验将：1）识别皮质 在自然视觉和眼球运动过程中的跨半球协调机制， 为将来的大脑半球间皮层通讯工作做准备; 2）建立一个精确的， 一个可靠的工具，用于识别皮层输入，以大大改善皮层电路的映射。

Abstract Visual-motor transformations and the generation of eye movements require processing that occurs in both brain hemispheres simultaneously. It is often assumed that the uninterrupted transfer of information from one hemisphere to the other and the resolution of competing movement plans are trivial problems. Yet this is unlikely the case because many visual-motor disorders have been linked to dysfunctions in inter-hemispheric communication, including strabismus, amblyopia, neglect, and epilepsy. Thus, inter-hemispheric communication is an understudied but central part of brain function. The ability to record from both hemispheres simultaneously and identify the exact neuronal connections between them has traditionally been difficult to accomplish. However, we recently developed optogenetic tools that reliably locate and label the cross-hemisphere inputs to a particular brain region. Coupled with modern techniques for recording neuronal populations, this approach promises to usher in a new era of primate-centric research that maps the brain circuitry needed to combine cortical activity in both hemispheres to generate an unambiguous percept and plan a specific action. The ability to directly link neuronal connections between brain hemispheres with their functional role in visual-motor behavior provides a powerful tool for investigating the longstanding hypothesis that activity for a specific movement vector in one hemisphere inhibits dissimilar movement activity in the other. We propose experiments that test this hypothesis by capitalizing on the well-characterized, precisely measurable, and naturalistic nature of eye movements and their cortical control by the frontal eye fields (FEF). In our first specific aim, we will optically identify and activate neurons in one FEF that project across the hemispheres while recording from recipient neurons in the other FEF to determine whether increased activity in one hemisphere decreases the activity of recipient neurons with dissimilar direction preferences in the other hemisphere. Our second specific aim will use a similar setup but inhibit the activity of cross-hemisphere cortical inputs to more thoroughly test the network architecture that governs inter-hemispheric communication. Collectively, the proposed experiments will: 1) identify cortical mechanisms for cross-hemispheric coordination during natural vision and eye movements, in preparation for future work on interhemispheric cortical communication; 2) establish a precise, reliable tool for identifying cortical inputs to greatly improve the mapping of cortical circuitry.