Spectral and spatial processing of wavelength information in the Drosophila visual system

果蝇视觉系统中波长信息的光谱和空间处理

• 批准号: 10219809
• 负责人: Sarah L Heath
• 金额: $ 4.55万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10219809
• 关键词: Animals; Anterior; Area; Axon; Brain; Brain region; Calcium; Cells; Characteristics; Color; Color Perception; Color Visions; Complex; Cues; Data; Dimensions; Drosophila genus; Drosophila melanogaster; Environment; Frequencies; Functional Imaging; Genetic; Image; Invertebrates; Lateral; Light; Location; Maps; Mediating; Memory; Methods; Nature; Neurons; Neurotransmitters; Optic Lobe; Optics; Organism; Output; Pathway interactions; Pattern; Photoreceptors; Presynaptic Terminals; Primates; Property; Regimen; Retina; Rhodopsin; Rodent; Route; Signal Transduction; Space Perception; Specificity; Stimulus; Structure; System; Techniques; Testing; Visual; Visual Fields; Visual Perception; Visual system structure; base; color constancy; combinatorial; experimental study; fly; genetic manipulation; horizontal cell; in vivo; in vivo calcium imaging; insight; mutant; neuromechanism; object recognition; preservation; receptive field; receptor; response; spatial integration; tool; two-photon; visual information; visual process; visual processing

Project Summary / Abstract Our surroundings are extremely rich in spectral information, which confers a valuable chromatic dimension to visual perception. In order to have the capacity for color vision, an organism must be able to perform the necessary computations to compare light of different spectral compositions. Wavelength comparison takes place in color opponent neurons, which respond with opposite polarity to wavelengths in different parts of the spectrum. Despite advances in our understanding of color opponency in the brain, how color opponent signals are transformed to give rise to the hue specificity observed in higher cortical regions remains completely unexplained. Furthermore, how wavelength information is integrated across the visual field to provide a spatial dimension to color vision is a poorly understood phenomenon. This project aims to examine color pathways in the genetically tractable organism Drosophila melanogaster, as these circuits have only just begun to be described. Drosophila provide an arsenal of genetic tools to manipulate neuronal activity and a simple brain that makes these circuits tractable. Fruit flies have the hardware for wavelength comparison, with wavelength-specific photoreceptors (called R7s and R8s) expressing rhodopsins sensitive to UV, green, and blue light. There is mounting evidence that color opponency is indeed present in the brain of the fruit fly, arising in the axons of R7/R8. Aim 1 will determine how signals are combined at the level of photoreceptors to give rise to opponency by using two-photon calcium imaging of R7/R8 axons in a variety of genetic backgrounds, including mutants, pairwise rescues, and lines with cell-specific silencing. Aim 2 will elucidate the spatial nature of opponency in Drosophila photoreceptors, taking advantage of the fact that spatially patterned stimuli will reveal potential center-surround mechanisms when paired with functional imaging of R7/R8 axons. Finally, Aim 3 will explore the encoding of both spectral and spatial information in downstream brain areas poised to both receive signals from photoreceptors, and to further transmit these signals to central brain regions. There is evidence that this information eventually informs tasks such as object recognition and spatial orientation. Determining how circuit mechanisms for spatio-chromatic processing emerge and convey information to higher brain areas in Drosophila will provide insight into the workings of vertebrate color pathways, as both systems employ similar mechanisms to effectively process visual information.

项目摘要 /摘要 我们的周围环境非常丰富，光谱信息赋予了宝贵的色彩 视觉感知的维度。为了具有颜色视觉的能力，有机体必须能够 执行必要的计算以比较不同光谱组成的光。波长 比较发生在彩色对手神经元中，该神经元与波长相反的极性响应 频谱的不同部分。尽管我们对大脑中颜色反对的理解有所进步，但如何 颜色对手信号被转换为产生高层皮质区域中观察到的色调特异性 仍然完全无法解释。此外，如何在视野中整合波长信息 为了为色觉提供空间维度是一种鲜为人知的现象。这个项目旨在 检查遗传性可牵引有机体果蝇中的颜色途径，因为这些电路具有 只是才开始描述。果蝇提供了操纵神经元活动的遗传工具的库 和一个简单的大脑，使这些电路可拖动。水果苍蝇具有波长的硬件 比较，表达对敏感的视紫红蛋白的波长特异性光感受器（称为R7和R8S） 紫外线，绿色和蓝光。有越来越多的证据表明颜色反对确实存在于大脑中 果蝇在R7/R8的轴突中产生。 AIM 1将确定信号如何在 通过使用多种R7/R8轴突的两光子钙成像引起对立的感光体 遗传背景，包括突变体，成对救援和带有细胞特异性沉默的线。目标2将 利用这一事实，阐明了果蝇感光体中反对性的空间性质 当与功能配对时 R7/R8轴突的成像。最后，AIM 3将探讨光谱和空间信息的编码 有助于两者都从感光器接收信号的下游大脑区域，并进一步传输这些信号 向中央大脑区域的信号。有证据表明，这些信息最终会告知诸如对象之类的任务 识别和空间取向。确定如何进行时空处理的电路机制 出现并传达信息到果蝇的较高大脑区域将提供有关的洞察力 脊椎动物的颜色途径，因为这两个系统都采用相似的机制来有效地处理视觉 信息。