Finding time for dinner: real-time bioluminescence reporting of circadian gene expression in food-entrained rodents

找到吃晚饭的时间：食物夹带的啮齿动物昼夜节律基因表达的实时生物发光报告

• 批准号: 374998-2009
• 负责人: Mistlberger, Ralph
• 金额: $ 5.15万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=412056
• 关键词: Finding; time; dinner; real; bioluminescence

The behaviour and physiology of mammals is regulated by endogenous circadian (24 h) clocks in the brain and in peripheral organs and tissues. These clocks generate daily rhythms of sleep-wake, appetite and body temperature and coordinate the functions of all organ systems with daily cycles of light-dark and mealtimes. A master circadian clock located in the hypothalamus is critical for synchronizing daily rhythms to light-dark cycles, but is only indirectly involved in synchrony to daily mealtimes. Our research aims to understand the brain mechanisms by which daily rhythms of behaviour and physiology are synchronized to predictable daily mealtimes. Recent advances in the molecular biology of circadian timekeeping have identified a number of genes that exhibit circadian rhythms of expression, and that form interlocking negative and positive feedback loops that produce self-sustaining, cell autonomous rhythmicity. Transgenic rats and mice are now available in which the firefly luciferase gene has been fused with the promotor of one of these circadian clock genes, such that brain and organ tissues emit light when the clock gene is expressed. Tissue from specific brain regions and peripheral organs can be extracted and maintained for many weeks in culture, during which bioluminescence can be measure continuously, in real time, by photometry. We will use this equipment grant to purchase a photometry system with which we will address fundamental questions about the organization of the brain system that generates food-synchronized daily rhythms. Specific objectives will be to 1. determine the location in the brain (or periphery) of the circadian clocks that control food-synchronized behavioral, autonomic and endocrine rhythms, 2. determine whether synchrony of rhythms to 2 or more daily mealtimes involves a single or a multiple clock system, and 3. determine how the timing of feeding and fasting affects the rate at which circadian rhythms reset in response to a shift of the daily light-dark cycle. This information will help us understand how the brain regulates daily rhythms, and how meal timing may be used to minimize disruption of circadian timekeeping following shifts of light-dark.

哺乳动物的行为和生理是由大脑和外周器官和组织中的内源性昼夜节律（24小时）时钟调节的。这些生物钟产生每天的睡眠-觉醒、食欲和体温的节律，并协调所有器官系统的功能与每天的明暗和用餐时间的周期。位于下丘脑的主生物钟对于使每日节律与明暗周期同步至关重要，但仅间接参与每日进餐时间的同步。我们的研究旨在了解日常行为和生理节奏与可预测的每日用餐时间同步的大脑机制。生物钟计时的分子生物学的最新进展已经确定了许多表现出昼夜节律表达的基因，并形成互锁的负反馈和正反馈回路，产生自我维持的细胞自主节律。转基因大鼠和小鼠现在是可用的，其中萤火虫荧光素酶基因已经与这些生物钟基因之一的启动子融合，使得大脑和器官组织在生物钟基因表达时发光。可以提取来自特定脑区域和外周器官的组织并在培养物中保持数周，在此期间可以通过光度法连续地、真实的地测量生物发光。 我们将利用这笔设备补助金购买一个测光系统，我们将解决有关大脑系统组织的基本问题，该系统产生与食物同步的日常节奏。具体目标将为1.确定控制食物同步的行为、自主和内分泌节律的生物钟在大脑（或外周）中的位置，2.确定节律与2个或更多个每日进餐时间的同步是否涉及单个或多个时钟系统，以及3.确定进食和禁食的时间如何影响昼夜节律响应每日明暗周期变化而重置的速率。这些信息将帮助我们了解大脑如何调节日常节奏，以及如何使用进餐时间来最大限度地减少昼夜节律计时的中断。