The neural circuitry of learning, memory, and decision-making in honey bees

西方蜜蜂（Apis mellifera）以其复杂的行为而闻名。它可以了解一天中食物供应的时间以及多个同时食物源的供应位置。它可以记忆和计算地标，并遵循天空中的紫外线模式（“太阳罗盘”）来导航到已知的食物来源。然后，它可以返回家中，通过一种称为“摇摆舞”的符号语言将食物源的位置传达给它的蜂巢伙伴，其中食物源的方向和距离是通过身体动作来传达的。人类利用蜜蜂获取蜂蜜和蜡已有 9000 年的历史，并且积极饲养驯养蜜蜂的历史有一半时间。然而，尽管亚里士多德也养过蜜蜂，但仔细的蜜蜂实验直到 18 世纪才开始。即使现在，我们才刚刚开始了解任何动物行为的神经基础。神经行为学是从进化和比较的角度研究大脑结构和功能的学科。它主要关注大脑如何产生行为。由于蜜蜂的大脑对于昆虫来说异常大，大小约为 1 立方毫米，包含近 100 万个神经元，并且由于蜜蜂拥有如此令人印象深刻的复杂行为，因此蜜蜂是神经行为学中理想的研究动物。发现蜜蜂大脑如何产生行为是我研究项目的长期目标。在这个资助周期中，我的实验室将继续探索昆虫大脑中重要区域蘑菇体（MB）的组织，该区域参与感觉统合、学习和记忆。我们将训练蜜蜂执行复杂的感官学习任务，并研究这些信息如何在大脑中编码。我们还将研究大脑如何因这些经历而发生变化。有限的证据表明学习发生在 MB 输入区域（肾盏）和 MB 输出区域（叶）。我们最终将了解如何组合这些信息并与大脑中的其他信息流进行比较，以了解如何做出决策。这项工作之所以重要有两个原因。首先，虽然昆虫的大脑与人类的大脑不同，但在很大程度上，神经元就是神经元。了解更容易处理的大脑的结构和功能将指导我们尝试了解人类的大脑结构和功能（以及功能丧失）。其次，传粉媒介的健康目前在全世界范围内受到严重关注。随着栖息地的丧失、农药使用量的增加以及新的入侵性害虫的出现，授粉媒介的数量几十年来一直在下降。仅蜜蜂授粉一项在加拿大就是一个价值 25 亿美元的产业，在全世界也是一个价值 2000 亿美元的产业。考虑到传粉媒介负责我们大约三分之一的食物，解决昆虫的感觉统合、学习和决策问题至关重要，并且可能会带来生态系统服务的新工具，提高传粉媒介的效率，并可能提高作物产量。

The western honey bee (Apis mellifera) is renowned for its complex behaviour. It can learn the times of day of food availability and the locations of availability for multiple simultaneous food sources. It can memorize and count landmarks and follow UV light patterns in the sky (the "sun compass") to navigate to known food sources. It can then return home and communicate the locations of food sources to its hivemates via a symbolic language called the "waggle dance", wherein the direction and distance of the source are communicated by body movements. Humans have exploited bees for honey and wax for 9000 years and actively kept domesticated bees for half that time. However, while even Aristotle was known to keep bees, careful bee experimentation did not begin until the 18th century. Even now, we are only beginning to understand the neural underpinnings of behaviour in any animal. Neuroethology is the study of brain structure and function from an evolutionary and comparative perspective. It focuses largely on how brains produce behaviour. Because the honey bee has an unusually large brain for an insect, measuring about 1 mm3 and containing nearly 1 million neurons, and because the honey bee possesses such an impressive repertoire of complex behaviours, the honey bee is an ideal research animal in neuroethology. Discovering how honey bee brains produce behaviour is the long-term objective of my research program. In this grant cycle, my lab will continue to explore the organization of an important insect brain region called the mushroom bodies (MB), which are involved in sensory integration, learning, and memory. We will train bees to perform complicated sensory learning tasks and look at how this information is coded in the brain. We will also look at how the brain changes due to these experiences. There is limited evidence that learning occurs both in the MB input regions (the calyces) and the MB output regions (the lobes). We will ultimately learn how this information is combined and compared with other information streams in the brain to understand how decisions are made. This work is important for two reasons. First, while insect brains are different than human brains, to a large extent a neuron is a neuron. Understanding structure and function in a more tractable brain will guide us as we try to understand brain structure and function (and loss of function) in humans. Second, pollinator health is of serious concern worldwide right now. With loss of habitat, increased pesticide use, and new invasive pests, pollinator numbers have been declining for decades. Honey bee pollination alone is a $2.5 billion industry in Canada and a $200 billion industry worldwide. Considering pollinators are responsible for about a third of our food, solving problems in sensory integration, learning, and decision making in insects is critical and may lead to novel tools in ecosystem service, increasing pollinator efficiency, and possibly increasing crop yield.