Circuit Mechansims of Color Preference

自19世纪以来，理解人类对颜色的偏好仍然是心理物理学的一个持久挑战。虽然已经提出了一些一般原则，但颜色偏好的基本生物学仍然难以捉摸，这主要是由于影响人类颜色偏好的许多混杂因素以及解决这些因素的技术挑战。使用简单的果蝇已经使用了100多年来解决基本的神经生物学问题，PI最近建立了一个新的范式来研究果蝇对色光的反应。结果颠覆了该领域先前的几个教条，并首次揭示了颜色光偏好随一天中的时间而有节奏地变化。这种时间依赖性突出了一个以前未知的监管原则，并表明，在动物的颜色选择的透彻理解必须考虑到日常变化。该提案将利用果蝇中强大的遗传工具来描述和表征控制这些颜色偏好节律变化的神经回路。假设的电路将光信息与外部温度和苍蝇大脑中内置时钟网络的输出相结合。这些系统中的每一个-视觉，温度感觉和内源性时钟-在苍蝇和人类之间有相当大的神经生物学重叠。因此，该项目的结果预计将为理解人类颜色偏好的生物控制提供重要的概念性进展。本科生和研究生受训人员将参与开展拟议的实验，通过出版物和科学讲座传播成果，并帮助PI开展涉及当地中学生的教育活动。该项目将利用一种新颖的多色范例来描述一种集成光、温度和时间输入的电路，以调节果蝇的先天颜色偏好。如果苍蝇可以选择不同颜色的照明区域，它们会选择绿色和暗淡的，这取决于一天中的时间。这种偏好依赖于眼睛、天线、热感觉通道，并受到大脑生物钟的调节。这些发现假设了一个电路，该电路将来自光感受器的光信号和昼夜信号与来自外周和内部温度计的温度信号相结合。合并后的信号流经背外侧时钟神经元，然后撞击下游电路。具体来说，该项目将利用Gal4/UAS系统分别识别一个热敏电路和一个正常控制颜色偏好所需的时钟神经元的最小子集。研究还将利用已知的神经肽信号传导网络来识别在外侧神经元下游的颜色偏好中作为多感觉整合位点的细胞。快速作用的神经递质，如章鱼胺和5-羟色胺，已知介导进入苍蝇神经系统的感觉输入，该项目将定义对温度和光输入到颜色偏好至关重要的神经递质受体。 通过这些研究，该项目将为从电路层面理解先天颜色偏好奠定基础。该项目的科学成果将被纳入推广活动，以促进中学生的STEM教育。所有活动将涉及PI与研究生和本科生学员，他们将共同传播通过同行评审的出版物和演示文稿的研究结果。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Understanding human preference for colors remains an enduring challenge in psychophysics since the 1800’s. While some general principles have been proposed, underlying biology of color preference remains elusive due largely to the many confounding factors that affect human color preference and the technical challenges associated in addressing them. Using the simple fruit fly which has been used for over 100 years to address basic neurobiological questions, the PI has recently established a new paradigm to investigate fly response to color light. The results upended several prior dogma in the field and revealed for the first time that color light preference changes rhythmically with the time of day. This time-dependence highlights a previously unknown regulatory principle and suggests that a thorough understanding of color choice in animals must account for the daily variations. The proposal will take advantage of the powerful genetic tools available in the fruit fly to describe and characterize a neural circuit that controls these rhythmic changes in color preference. The hypothesized circuit combines light information with external temperature and output of the built-in clock network in the fly brain. Each of these systems---visual, thermosensory and endogenous clock---has considerable neurobiological overlap between flies and humans. Therefore, results from the project are anticipated to provide major conceptual advances towards understanding biological control of color preference in humans. Undergraduate and graduate trainees will be engaged in carrying out proposed experiments, in disseminating results through publications and scientific talks, and in helping the PI with educational activities involving local middle-school students. This project will leverage a novel multi-color paradigm to describe a circuit that integrates light, temperature and time inputs to adjust innate color preference in fruit flies. Flies given a choice of color-light illuminated areas, prefer green and dim in a time-of-day dependent manner. The preference relies on the eyes, the antenna, thermosensory channels and modulated by the brain’s circadian clock. These findings hypothesize a circuit that incorporates photic and circadian signals from photoreceptors with temperature signal from peripheral and internal thermometers. The combined signal flows through dorsolateral clock neurons before impinging on downstream circuits. Specifically, the project will utilize the Gal4/UAS system to separately identify a thermosensory circuit and a minimal subset of clock neurons needed for normal control of color preference. Studies will also leverage known neuropeptide signaling network to identify cells that function as a site for multisensory integration in color preference downstream of lateral neurons. Fast-acting neurotransmitters, like octopamine and serotonin, are known to mediate sensory inputs into the fly nervous system and this project will define neurotransmitter receptors that are critical for temperature and photic inputs into color preference. Through these studies, the project will lay the foundation for a circuit-level understanding of innate color preference. Scientific results from the project will be integrated into outreach activities that will promote STEM education among middle-school students. All activities will involve the PI with graduate and undergraduate trainees, who will together disseminate the findings through peer-reviewed publications and presentations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.