Mechanisms of chemosensory behavioral plasticity in C. elegans

所有动物都能感觉到环境中的多种化学物质，并对其做出反应。化学信号表明食物、配偶、捕食者和有毒物质的存在，动物被吸引、排斥或对个别气味漠不关心。然而，动物对化学物质的反应不是固定的，而是可以根据它们过去的经验和目前的状态来改变的。例如，长时间暴露在气味中会降低对该化学物质的后续反应，青少年和成年人对化学物质的反应可能会不同。这种灵活性确保了动物表现出最适合其当前状况的行为。这个项目的总体目标是探索动物的经历及其发育阶段如何改变神经系统的功能，以驱动不同的化学感知行为。鉴于气味和味道在动物生命周期中的重要性，这项工作使我们能够开始探索环境的变化如何影响动物的福利，并帮助畜牧业和保护工作。拟议的工作支持对高中、本科生和研究生以及博士后研究员的培训，并将尽一切努力让代表性不足的少数群体成员参与进来。该项目还在大学实验室与高中生和教师之间建立了研究关系。这项工作的真知灼见通过在当地科学博物馆和科学博览会上的实践演示与公众分享。这项拟议的工作还包括生物学家、化学家和生物工程师之间的合作，因此有望促进跨学科的学习和创新。先天和后天行为都是灵活的，广泛地受到动物的经验以及其外部和内部状态的调节。这项建议的具体目标是识别和表征调节线虫化学感觉行为反应中上下文和发育阶段特异性可塑性的分子、神经元和电路。初步实验表明，背景线索调节了拮抗神经回路的输出，从而在吸引和厌恶之间切换对简单酒精的反应。这种反应灵活性背后的行为策略和神经元机制是通过对特定条件下的行为状态和神经元活动的高分辨率分析来表征的。线虫的化学感觉行为也作为发育阶段和环境经验的函数被戏剧性地调节。这项拟议的研究描述了这种依赖于经验和阶段的化学感觉行为可塑性，并确定了所需的神经元和分子机制。这项工作的结果为动物有效地改变其行为以应对不断变化的外部和内部条件的机制提供了新的信息。

All animals sense and respond to multiple chemicals in their environment. Chemical cues signal the presence of food, mates, predators, and toxic substances, and animals are attracted, repelled, or indifferent to individual odors. However, the responses of animals to chemicals are not fixed, but can be altered by their past experience and current state. For example, prolonged prior exposure to an odor decreases subsequent responses to that chemical, and juveniles and adults can exhibit different responses to chemicals. This flexibility ensures that the animal exhibits the behavior that is most appropriate for its current condition. The overall goal of this project is to explore how an animal's experience and its developmental stage alter the functions of the nervous system to drive different chemical-sensing behaviors. Given the importance of smell and taste in animal lifecycles, this work allows us to begin to explore how changes in the environment may impact animal welfare, and aid in animal husbandry and conservation efforts. The proposed work supports the training of high school, undergraduate and graduate students, and postdoctoral fellows, and all efforts will be made to involve members of underrepresented minority groups. The project also builds research relationships between university labs and high school students and teachers. The insights from this work are shared with the public via hands-on demonstrations at local science museums and science fairs. The proposed work also incorporates collaborations among biologists, chemists and bioengineers, and is thus expected to promote interdisciplinary learning and innovation.Both innate and learned behaviors are flexible, and are extensively modulated by an animal's experience as well as its external and internal state. The specific goal of this proposal is to identify and characterize the molecules, neurons, and circuits that mediate context- and developmental stage-specific plasticity in chemosensory behavioral responses of the nematode C. elegans. Preliminary experiments suggest that contextual cues modulate the output of antagonistic neural circuits to toggle the response to a simple alcohol between attraction and aversion. The behavioral strategies and neuronal mechanisms underlying this response flexibility is characterized using high-resolution analyses of behavioral states and neuronal activity under defined conditions. C. elegans chemosensory behaviors are also dramatically modulated as a function of developmental stage and environmental experience. The proposed research characterizes this experience- and stage-dependent chemosensory behavioral plasticity, and identifies the required neuronal and molecular mechanisms. Results from this work provide new information about the mechanisms by which animals efficiently alter their behaviors in response to changing external and internal conditions.