Synaptic Organization and Function of Retinal Interneurons and Downstream Visual Pathways

视网膜中间神经元和下游视觉通路的突触组织和功能

• 批准号: 10388238
• 负责人: Daniel Kerschensteiner
• 金额: $ 38.19万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10388238
• 关键词: Address; Amacrine Cells; Animals; Award; Axon; Behavior; Behavior Control; Behavioral Assay; Benchmarking; Brain; Brain Diseases; Calcium; Caliber; Categories; Cell Shape; Cell physiology; Computer Models; Data; Dendrites; Early identification; Electron Microscopy; Environment; Freezing; Functional disorder; Glutamates; Glycine; Goals; Grant; Health; Human; Image; Insecta; Interneurons; Knowledge; Link; Mediating; Methods; Morphology; Mus; Neurons; Neurosciences; Neurotransmitters; Output; Pathway interactions; Resolution; Retina; Retinal Diseases; Retinal Ganglion Cells; SLC17A8 gene; Sensory; Signal Transduction; Stimulus; Synapses; System; Techniques; Testing; Tissues; Vesicle; Vision; Visual; Visual Pathways; base; behavioral response; brain behavior; cell type; electric impedance; experimental study; follow-up; ganglion cell; genetic manipulation; insight; optogenetics; relating to nervous system; response; sight restoration; superior colliculus Corpora quadrigemina; synaptic inhibition; transmission process; two-photon; visual processing

Project Summary All animals need to detect threats in their environment to survive. Objects on a collision course cast expanding shadows on the retina (i.e., looming) that elicit innate defensive responses from insects to humans. During the previous award of this grant, we discovered that a retinal interneuron, the VGLUT3-expressing amacrine cell (VG3-AC), detects looming and drives innate defensive responses in mice. Here, we follow up on this discovery to understand how dendritic processing gives rise to feature-selective responses of VG3-ACs (Aim 1), and how VG3-ACs use dual transmitters (glutamate and glycine) to generate divergent feature representations downstream and guide behavior (Aim 2). Dendritic processing and dual transmission are features of subcellular modularity, which we propose as an organizing principle of interneurons. To explore subcellular modularity, we developed methods to combine two-photon calcium imaging and serial-section electron microscopy in the same tissue (i.e., functional connectomics). In Aim 1, we will combine functional connectomics with computational modeling and cell-type-specific genetic manipulations to test the hypotheses that synaptic inhibition and arbor morphology compartmentalize VG3-AC dendrites and that dendritic compartmentalization generates looming- selective responses. In Aim 2, we combine functional connectomics, optogenetics, and cell-type-specific genetic manipulations, to test the hypotheses that VG3-ACs use glutamate and glycine to communicate their responses with opposite sign to two categories of ganglion cells and that this target-specific use of dual transmitters generates divergent representations of looming in the retinal output. We know little about how retinal processing relates to visual processing in the brain and behavior. To fill this gap in our knowledge, we have established projection-specific large-scale recordings from retinal ganglion cells, large-scale recordings from subcortical ganglion cell targets, and behavioral assays. This allows us to track how looming signals of VG3-AC dendrites are transformed across subsequent stages of processing to guide behavior. In Aim 1, we will test the hypotheses that downstream neurons lose their feature selectivity and that innate defensive responses generalize to non- threatening stimuli when dendritic processing of VG3-ACs is disrupted (i.e., when local processing becomes global). In Aim 2, we will test the hypothesis that VG3-ACs use glutamate and glycine to generate impressed- and suppressed-by-looming responses in two categories of ganglion cells and that these ganglion cells converge in the superior colliculus to drive defensive behaviors and control the contrast gain of these responses, respectively. Together, our studies will provide insights into the specifics and general principles of interneuron organization, mechanisms, and functions and bridge that gap in our understanding from retinal processing to visual processing in the brain and behavior for a conserved retinal interneuron and its downstream pathways performing a conserved visual computation that drives a survival behavior.

项目摘要 所有的动物都需要发现环境中的威胁才能生存。碰撞过程中的物体投射展开 视网膜上的阴影（即，隐约可见），引发昆虫对人类的先天防御反应。期间 在此之前，我们发现视网膜中间神经元，即表达VGLUT 3的无长突细胞， （VG 3-AC），检测隐约出现的并驱动小鼠的先天防御反应。在这里，我们继续这个发现 了解树突状处理如何引起VG 3-AC的特征选择性反应（目的1），以及如何 VG 3-AC使用双递质（谷氨酸和甘氨酸）生成发散特征表示 下游和引导行为（目标2）。树突加工和双重传输是亚细胞的特征 模块化，我们建议作为interneurons的组织原则。为了探索亚细胞模块化，我们 将联合收割机双光子钙成像和连续切片电子显微镜结合在一起的方法 组织（即，功能性连接组学）。在目标1中，我们将联合收割机与计算结合起来 建模和细胞类型特异性遗传操作，以测试突触抑制和乔木 形态划分VG 3-AC树突，树突划分产生隐约可见的- 选择性反应。在目标2中，我们将联合收割机功能性连接组学、光遗传学和细胞类型特异性遗传学结合起来， 操作，以测试VG 3-AC使用谷氨酸和甘氨酸来传达其响应的假设 与两类神经节细胞相反的符号，这种目标特异性使用双递质 在视网膜输出中产生不同的隐约呈现。我们对视网膜的加工过程知之甚少 与大脑中的视觉处理和行为有关。为了填补我们知识的空白，我们建立了 视网膜神经节细胞的投影特异性大规模记录、皮质下的大规模记录 神经节细胞靶标和行为测定。这使我们能够追踪VG 3-AC树突的隐约信号 在随后的处理阶段中被转化，以指导行为。在目标1中，我们将检验假设 下游神经元失去了它们的特征选择性，先天的防御反应一般化为非- 当VG 3-AC的树突加工被破坏时的威胁性刺激（即，当本地处理成为 global）。在目标2中，我们将测试以下假设：VG 3-AC使用谷氨酸和甘氨酸来产生印象- 以及两类神经节细胞的隐现反应， 在上级丘中驱动防御行为并控制这些反应的对比度增益， 分别总之，我们的研究将提供深入了解interneuron的具体和一般原则， 组织，机制和功能，并弥合我们从视网膜处理到 一个保守的视网膜中间神经元及其下游通路的大脑视觉加工和行为 执行保守的视觉计算，驱动生存行为。