Dissecting the visuomotor circuit for saccadic suppression in the mouse superior colliculus

项目总结 许多物种，包括老鼠，使用被称为扫视的弹道重定向动作来积极探索它们的 显著刺激的环境。眼跳会导致视觉感知的短暂改变，从而使它 看不到眼跳前后出现的视觉刺激。这种现象被称为 眼跳抑制，它与整个视觉系统的神经活动减少有关。融合 一系列证据表明，这种眼跳抑制的神经关联来自视觉和 前置马达机构。一些研究表明，模拟自产生的运动与 眼跳足以降低视网膜的视觉敏感度，并复制知觉缺陷 与实际的扫视有关。补充性研究假设眼跳运动计划是 广播到视觉系统，在那里它被用来在眼球跳动期间抑制视觉活动。这 得到了一些研究的支持，这些研究证明了在下列条件下眼跳抑制的持久性 最小化或排除视觉机制的影响。在这个提案中，我们试图理解视觉是如何 跳动抑制的前置运动部分由神经电路实现。我们将专注于我们的 视觉运动性脑结构--中脑上丘的研究 被怀疑是眼跳前后抑制视觉活动的必然放电的来源。 我们想补充这一观点，即视网膜的视觉输出本身受到眼跳的调节。我们 假设上丘脑运动前活动的必然放电和眼球跳动周围调制 视网膜信号的协同作用在SC的浅层产生视觉活动抑制 大约在扫视的时候。在提案的目标1中，我们将使用以下内容剖析SC中的前置电机电路 光遗传学、化学遗传学和高密度活体记录单个单位的活动而小鼠 扫视。在本提案的目标2中，我们将检查SC投射的视网膜神经节细胞是否存在眼球跳动。 使用双光子钙成像和自然视觉刺激进行调制。对公共卫生的意义。这 该提案旨在了解如何通过解剖视觉和前运动来实现眼跳抑制 中脑SC的回路。这项研究将促进我们对稳定和稳定的神经基础的理解。 跨眼跳的连续视觉感知对于正常视觉行为的进行是至关重要的。在……里面 此外，这项研究可能会改进对以下伤害和疾病的诊断和治疗 影响眼球运动系统。

PROJECT SUMMARY Many species, including mice, use ballistic reorienting movements called saccades to actively explore their environment for salient stimuli. Saccades result in a transient modification of visual perception such that it becomes difficult to see visual stimuli which appear around the time of saccades. This phenomenon is called saccadic suppression and it is associated with a decrease in neural activity across the visual system. Converging lines of evidence show that this neural correlate of saccadic suppression arises from a combination of visual and premotor mechanisms. Several studies have shown that the simulating the self-generated motion associated with saccades is sufficient to reduce visual sensitivity in the retina and reproduces the perceptual deficits associated with actual saccades. Complementary studies have hypothesized that the saccade motor plan is broadcast to the visual system where it is used to suppress visual activity during the peri-saccadic epoch. This is supported by studies which demonstrate the persistence of saccadic suppression under conditions which minimize or preclude the effect of visual mechanisms. In this proposal, we seek to understand how the visual and premotor components of saccadic suppression are implemented by neural circuits. We will focus our investigation on the midbrain superior colliculus (SC), a visuomotor brain structure which has long been suspected as the source of a corollary discharge that suppresses visual activity around the time of saccades. We would like to add to this idea that the visual output of the retina is itself modulated by saccades. We hypothesize that a corollary discharge of premotor activity in the SC and the peri-saccadic modulation of retinal signals cooperate to produce suppression of visual activity in the superficial layers of the SC around the time of saccades. In Aim 1 of the proposal, we will dissect the premotor circuitry in the SC using optogenetics, chemogenetics, and high-density in vivo recordings of single-unit activity while mice make saccades. In Aim 2 of this proposal, we will examine SC-projecting retinal ganglion cells for peri-saccadic modulation using two-photon calcium imaging and naturalistic visual stimulation. Public health significance. This proposal aims to understand how saccadic suppression is implemented by dissecting the visual and premotor circuitry in the midbrain SC. This research will advance our understanding of the neural basis for stable and continuous visual perception across saccades which is critical for the conduct of normal visual behavior. In addition, this research could lead to improvements in the diagnosis and treatment of injury and diseases which affect the oculomotor system.