Neural circuit mechanisms for color vision

色觉的神经回路机制

• 批准号: 10210514
• 负责人: Roudabeh Behnia
• 金额: $ 8.1万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2023-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10210514
• 关键词: Anatomy; Animal Model; Animals; Behavior; Behavioral Assay; Brain; Code; Color; Color Perception; Color Visions; Complex; Computational algorithm; Cone; Development; Discrimination; Drosophila genus; Drosophila melanogaster; Electrophysiology (science); Genetic; Genetic Models; Intention; Invertebrates; Investigation; Link; Methods; Modeling; Neurons; Organism; Parents; Pathology; Perception; Photoreceptors; Population; Problem Solving; Process; Research; Rhodopsin; Sensory; Signal Transduction; Synapses; System; Techniques; Vision; Visual; Visual system structure; cell type; connectome data; fly; in vivo two-photon imaging; neural circuit; neuromechanism; object recognition; postsynaptic; relating to nervous system; response; tool; visual processing

Project Summary (parent R01) Color vision is an important aspect of our perception of the world, enhancing our recognition of objects in complex visual scenes and allowing us to assign them an identity and quality. How are colors encoded in the brain? Despite decades of research, this question remains unanswered. It is widely accepted that color opponent neurons, responding with opposite polarity to wavelengths in different parts of the spectrum, are the building blocks for color vision. However, how color opponent neuron signals are combined to give rise to hue-specific neurons, with narrow spectral sensitivity, and how these neurons contribute to color perception is unknown. Analyses of color circuits in a genetically tractable organism are critical to answering these questions. Drosophila melanogaster provides a powerful system to investigate how a compact brain solves the problem of color coding, combining genetic access to cell-type-specific neural populations, a well-defined neural anatomy, and sophisticated behaviors. Moreover, vertebrate and invertebrate visual systems present many functional similarities. The fact that these diverse systems show convergence in solutions to visual processing problems motivates our investigation in a simple model, with the intention of extracting fundamental principles of relevance to mammalian systems. Fruit flies are capable color discrimination and have the hardware necessary for wavelength comparison: four types of cone-like photoreceptors each expressing a unique narrow-band rhodopsin of different wavelength sensitivity, ranging from UV to green. However, the way spectral information from these photoreceptors is processed in the brain is unknown and is the focus of this proposal. We will use genetic neural manipulation techniques, in vivo two-photon imaging, electrophysiology, and behavioral assays augmented by quantitative analysis and modeling, to identify the computational algorithms and neural mechanisms that govern color vision. Aim 1 will ask what kind of spectrally opponent mechanisms exist in Drosophila and determine the identity of neurons and synaptic interactions in the underlying circuits. We will, in addition, generate tools to disrupt color opponent signals. Aim 2 will use connectomics data in conjunction with tracing methods to define and functionally characterize color circuits postsynaptic to color photoreceptors. We will investigate how color-opponent signals are integrated to give rise to higher order color neurons. Aim 3 will characterize how the response of neurons in these circuits support both innate and learned color-guided behaviors, marking an experimental effort to draw a causal link between color opponency, color circuits and color perception, an approach that has been difficult in classical, non-genetically tractable, models for color vision. These studies will provide a detailed understanding of how spectral information is processed in the fly brain and serve as a guide to investigate wavelength computations underlying color vision in the brain of more complex animals.

项目摘要（父 R01） 色觉是我们感知世界的一个重要方面，它增强了我们对复杂物体的识别 视觉场景，让我们能够为它们分配身份和品质。颜色在大脑中是如何编码的？ 尽管经过了几十年的研究，这个问题仍然没有答案。人们普遍认为，颜色对手 神经元对光谱不同部分的波长做出相反的极性反应，是建筑物 色觉块。然而，颜色对手神经元信号如何组合以产生特定于色调的颜色 具有窄光谱敏感性的神经元，以及这些神经元如何促进颜色感知尚不清楚。 对遗传易处理生物体中颜色回路的分析对于回答这些问题至关重要。果蝇 黑腹果蝇提供了一个强大的系统来研究紧凑的大脑如何解决颜色编码问题， 结合对细胞类型特异性神经群体的遗传访问、明确的神经解剖学和 复杂的行为。此外，脊椎动物和无脊椎动物的视觉系统具有许多功能 相似之处。事实上，这些不同的系统在视觉处理问题的解决方案上表现出趋同性 激励我们在一个简单的模型中进行调查，目的是提取相关的基本原则 到哺乳动物系统。果蝇具有辨别颜色的能力，并且具有辨别颜色所需的硬件。 波长比较：四种锥状光感受器，每种都表达独特的窄带 视紫红质具有不同波长的敏感性，范围从紫外线到绿色。然而，光谱信息的方式 这些光感受器在大脑中的处理过程是未知的，也是本提案的重点。我们将使用 遗传神经操作技术、体内双光子成像、电生理学和行为测定 通过定量分析和建模来增强，以确定计算算法和神经网络 控制色觉的机制。目标 1 将询问存在什么样的光谱对手机制 果蝇并确定神经元的身份和底层电路中的突触相互作用。我们将在 此外，生成工具来干扰颜色对手信号。目标 2 将结合使用连接组学数据 追踪方法来定义和功能表征突触后到彩色感光器的颜色电路。我们 将研究如何整合颜色对手信号以产生更高阶的颜色神经元。目标3将 描述这些回路中神经元的反应如何支持先天和后天的颜色引导 行为，标志着一项实验性努力，旨在绘制颜色对立、颜色电路和颜色之间的因果关系 感知，这种方法在经典的、非基因可控的色觉模型中一直很困难。 这些研究将详细了解果蝇大脑中光谱信息的处理方式以及 作为研究更复杂的大脑中色觉基础的波长计算的指南 动物。