A serotonergic circuit controlling the circadian rhythm in Drosophila olfactory learning

内源性生物钟通过学习和学习的节奏来调节表现和认知功能。 不同物种的记忆都很明显。在我们的现代劳动力中，个人在不利的昼夜节律时间下工作，导致 除了经济成本和公共安全风险之外，这些人的认知能力受损 社会。此外，昼夜节律失调是一个日益严重的公共卫生问题，增加了以下疾病的风险： 神经退行性疾病和认知障碍，预计将带来巨大的经济负担 随着人口老龄化，我们的医疗保健系统受到影响。定义分子机制 生物钟目标学习对于确定不仅可以预防认知障碍而且可以预防认知障碍的方法至关重要 优化现代社会的表现和健康。增强学习和记忆能力 一天中的适应性时间将代表人类健康和表现的重大进步。长期来看 该项目的目标是定义中央昼夜节律所使用的神经回路和分子信号传导途径 振荡器加强果蝇嗅觉学习的节奏。果蝇表现出强大的 短期记忆形成中的昼夜节律。中央时钟神经元的身份和功能 果蝇的嗅觉学习回路已经很完善，有许多工具可用于操纵神经元 活性具有很强的特异性，使果蝇成为本研究的理想模型。中心假设是 内源性昼夜节律回路调节从血清素能 DAL 神经元到 蘑菇体，激活蘑菇体内的 5-HT1A 受体，导致昼夜节律 学习。拟议研究的基本原理是理解进化保守的机制 记忆获取的昼夜节律控制可用于更好地理解学习调节并 提高认知表现。这种理解将有两个具体目标： 1) 确定 背侧前外侧神经元在控制嗅觉学习昼夜节律中的作用。 2） 确定 α/β 后神经元中的 5HT1A 信号传导是否是嗅觉学习节律所必需的。的 所提出的实验将阐明时钟电路如何以及在何处改变学习电路。方法是 创新是因为它侧重于通过确定机制来提高认知表现 生物钟调节学习，以产生与一天中的时间相关的表现和认知下降 功能。这项研究意义重大，因为神经回路和分子机制 在任何系统中，人们对直接调节学习的内源时钟知之甚少。一天中的时间对的影响 认知表现很普遍，表现不一致的后果可能是毁灭性的 成本高昂。最终，了解记忆形成的昼夜节律控制的逻辑将允许进一步 致力于改善人类健康，减轻我们医疗保健系统的压力，并降低经济 神经退行性疾病和认知障碍带来的负担。

The endogenous circadian clock modulates performance and cognitive function with rhythms in learning and memory evident across species. In our modern workforce individuals work at adverse circadian times resulting in impaired cognitive performance in these individuals, in addition to economic costs and public safety risks to society. Furthermore, circadian desynchronization, a rising public health problem, increases the risk of neurodegenerative diseases and cognitive impairments, which is projected to put a substantial economic burden on our healthcare system as the population ages. Defining the molecular mechanisms through which the circadian clock targets learning is crucial to identifying methods to not only prevent cognitive impairments but to optimize performance and health in modern society. The ability to enhance learning and memory at non- adaptive times of day would represent a significant advance in human health and performance. The long-term goal of this project is to define the neural circuits and molecular signaling pathways used by the central circadian oscillator to enforce a rhythm in olfactory learning in Drosophila melanogaster. Drosophila displays a robust circadian rhythm in short-term memory formation. The identity and function of both central clock neurons and olfactory learning circuits are well established in Drosophila, with many tools available to manipulate neuronal activity with great specificity, making Drosophila an ideal model for this study. The central hypothesis is that the endogenous circadian circuit modulates neurotransmission from the serotonergic DAL neurons to the Mushroom Bodies, activating 5-HT1A receptors in the Mushroom Bodies, resulting in circadian rhythms in learning. The rationale for the proposed research is that understanding an evolutionarily conserved mechanism for the circadian control of memory acquisition can be used to understand learning modulation better and to improve cognitive performance. This understanding will be developed with two specific aims: 1) Determine the role of the Dorsal Anterior Lateral Neurons in controlling the circadian rhythm in olfactory learning. 2) Determine if 5HT1A signaling in the α/β posterior neurons is required for the rhythm in olfactory learning. The proposed experiments will elucidate how and where the clock circuit alters the learning circuit. The approach is innovative because it focuses on improving cognitive performance by identifying mechanisms through which the circadian clock regulates learning to produce time-of-day dependent decrements in performance and cognitive function. The proposed research is significant because the neurocircuitry and molecular mechanism by which endogenous clocks directly regulate learning are poorly understood in any system. The impact of time-of-day on cognitive performance is widespread, and the consequences of out-of-phase performance can be devastating and costly. Ultimately, understanding the logic underlying circadian control of memory formation will permit further work to improve human health, alleviate some of the pressure on our healthcare system, and lower the economic burden from neurodegenerative diseases and cognitive impairment.