Molecular and Neural Mechanisms regulating Foraging and Food Intake

调节觅食和食物摄入的分子和神经机制

• 批准号: 10387757
• 负责人: Nilay Yapici
• 金额: $ 10万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-07 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10387757
• 关键词: Administrative Supplement; Air Sacs; Animal Model; Animals; Behavior; Behavioral; Brain; Calcium; Cells; Chronic; Complex; Custom; Drosophila melanogaster; Eating; Esophagus; Esthesia; Fatty acid glycerol esters; Food; Food deprivation (experimental); Functional Imaging; Funding; Goals; Head; Hour; Hunger; Image; Imaging technology; Ingestion; Measurement; Metabolic; Methods; Microscope; Microscopy; Molecular; Mushroom Bodies; National Institute of General Medical Sciences; Neurobiology; Neurons; Neurosciences; Neurosciences Research; Odors; Optics; Performance; Physiological; Preparation; Research; Sensory; Structure; System; Taste Perception; Thirst; Time; Tissues; experimental study; fly; imaging modality; in vivo; multiphoton imaging; neural circuit; neuromechanism; neurophysiology; non-invasive imaging; relating to nervous system; response; transmission process

PROJECT SUMMARY The overall goal of NIGMS-funded research in my lab is to understand the fundamental principles of how the brain integrates the sensory percept of food with the sensation of hunger to regulate food intake on the level of molecules, cells and circuits. We are using the genetically tractable model organism, the fly (Drosophila melanogaster) to study how food intake circuits function and are regulated in the brain. One of the main aims of this project is to capture neural activity from circuits that regulate food intake when flies are changing their metabolic states. These experiments require non-invasive imaging of the fly brain at long time scales (>6 hours). Current methods used in fly optical neurophysiology do not allow such experiments because the cuticle-open imaging preparations that are commonly used in fly neuroscience research show reliable calcium responses for a maximum of ~3-4 hours before the fly brain starts degenerating. Recently, we have developed a non-invasive, chronic functional imaging method in flies. We first showed that, in contrast to a misconception in the field, the fly head cuticle has surprisingly high transmission at wavelengths > 900 nm, and the difficulty of through-cuticle imaging is due to the air sacs and/or fat tissue underneath the head cuticle. Removing air sacs completely or relocating them out of the imaging window by non-invasive compression of the fly head allows optical access to the fly brain without dissecting away the head cuticle. Using our through-cuticle imaging method, we first imaged the mushroom body Kenyon cells and the central complex ring neurons in the fly brain through the cuticle using 2P and 3P microscopy. Our measurements showed that 2P and 3P excitation performed similarly in shallow regions of the fly brain, but 3P excitation at 1320 nm is superior for deeper brain structures. We demonstrated the functional imaging performance of through-cuticle multiphoton imaging by capturing odor evoked calcium responses from mushroom body Kenyon cells expressing GCaMP6s in short-term and in long-term as flies are being food deprived. We plan to use through-cuticle functional imaging to capture the activity of neural circuits that regulate taste perception and food intake in flies. These neural circuits are located in deeply buried regions of the fly brain below the esophagus (subesophageal zone), therefore cannot be accessed with 2P excitation (920nm) through the cuticle. Therefore, our plan is to use 3P excitation (1320nm) to image these deep neural circuits in the intact fly brain through-cuticle. 3P-microscopy will enable chronic imaging of the taste sensitive neurons and food intake circuits as flies are changing their metabolic states and will allow us to answer important questions in neuroscience, such as: How do the taste circuits change activity when animals are changing their physiological states such as hunger/thirst? How do neural circuits encode behavioral states such as hunger/thirst? This project will not only push the limits of in vivo functional imaging in flies but also answer fundamental questions in neuroscience.

项目总结 在我的实验室里，NIGMS资助的研究的总体目标是理解 大脑将食物的感官知觉和饥饿感结合在一起，在 分子、细胞和电路。我们使用的是遗传上易驯服的模式生物--苍蝇(果蝇 研究食物摄取回路在大脑中是如何运作和调节的。的主要目标之一 这个项目是为了捕捉当苍蝇改变食欲时调节食物摄入量的回路的神经活动。 新陈代谢状态。这些实验需要在长时间尺度(&gt；6小时)对苍蝇大脑进行非侵入性成像。 目前在苍蝇视神经生理学中使用的方法不允许这样的实验，因为角质层开放 苍蝇神经科学研究中常用的成像制剂显示出可靠的钙反应 在苍蝇大脑开始退化之前，最多3-4个小时。最近，我们开发了一种非侵入性的， 苍蝇慢性功能显像法。我们首先证明，与该领域的一种误解相反， 苍蝇头角质层在900 nm波长有惊人的高透射率，而且穿透角质层的难度很大 成像是由于头部角质层下的气囊和/或脂肪组织。完全移除气囊或 通过对飞头的非侵入性压缩将它们重新定位在成像窗口之外允许光学访问 苍蝇的大脑不会解剖头部的角质层。使用我们的穿透角质层成像方法，我们首先成像 苍蝇脑中蘑菇体、Kenyon细胞和中央复合体环状神经元通过角质层的研究 2P和3P显微镜。我们的测量表明，2P和3P激发在浅层的表现相似 苍蝇脑的不同区域，但1320 nm处的3P激发对更深层的大脑结构更有利。我们演示了 嗅觉诱发钙离子经皮多光子成像的功能成像性能 蘑菇体Kenyon细胞表达GCaMP6的短期和长期反应 被剥夺食物。我们计划使用穿透角质层功能成像来捕捉神经回路的活动 调节苍蝇的味觉和食物摄入量。这些神经回路位于大脑的深埋区域 食道(食管下区)以下的苍蝇脑，因此不能用2P激发(920 Nm)访问 穿过角质层。因此，我们的计划是使用3P激发(1320 Nm)来成像这些深部神经电路 完整的苍蝇大脑穿透角质层。3P显微镜将使味觉敏感神经元和 苍蝇的食物摄取回路正在改变它们的代谢状态，这将使我们能够回答重要的问题 在神经科学中，例如：当动物改变其生理状态时，味觉回路如何改变活动 像饥饿/口渴这样的状态？神经回路如何对饥饿/口渴等行为状态进行编码？这个项目 将不仅推动苍蝇体内功能成像的极限，而且还将回答 神经科学。