Linking Molecular and Electrical Rhythms in the Brain's Biological Clock

连接大脑生物钟中的分子节律和电节律

• 批准号: 8546210
• 负责人: JEFFREY R JONES
• 金额: $ 2.69万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-05 至 2015-09-04
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8546210
• 关键词: Action Potentials; Address; Animals; Area; Autistic Disorder; Biological Clocks; Biological Models; Body Temperature; Brain; Circadian Rhythms; Conflict (Psychology); Disease; Electrophysiology (science); Endocrine; Feedback; Feeding behaviors; Fire - disasters; Fluorescence; Frequencies; Functional disorder; Gated Ion Channel; Gene Expression; Genes; Health; Human; Image; Individual; Ion Channel; Knock-out; Lead; Light; Link; Measures; Mental Depression; Metabolic Diseases; Methods; Molecular; Mus; Nervous system structure; Neurobiology; Neurons; Neurosciences; Output; Pacemakers; Periodicity; Phase; Physiological Processes; Play; Research; Role; Signal Transduction; Sleep Disorders; Sleep Wake Cycle; Synaptic plasticity; Techniques; Testing; Time; Training; Transcriptional Activation; Transgenic Mice; Work; circadian pacemaker; improved; insight; light gated; neurodevelopment; neuropsychiatry; novel; optogenetics; overexpression; promoter; recombinase; skills; suprachiasmatic nucleus

DESCRIPTION (provided by applicant): Understanding the interaction between gene expression and electrical activity in the nervous system is an essential problem in neuroscience that has broad impacts on such areas as synaptic plasticity and neurodevelopment. A useful model system to study this interaction is the brain's biological clock, the suprachiasmatic nucleus (SCN). The SCN generates endogenous molecular and electrical circadian rhythms that together regulate a multitude of physiological processes. Disrupted circadian rhythms have the potential to influence a range of human health conditions such as sleep and metabolic disorders and neuropsychiatric illnesses such as autism and depression. To understand how the dysregulation of circadian clock components may lead to disease, it is first necessary to understand how they work in a healthy brain. A key unsolved question in circadian neurobiology is how the SCN's molecular and electrical rhythms interact to form a coherent pacemaker. SCN neurons are autonomous oscillators that possess daily molecular transcriptional- translational feedback loops involving the core clock genes Per1/2, Cry1/2, Bmal1, and Clock. These neurons can spontaneously fire action potentials, and, importantly, can modulate their firing rates so that they fire quickly during the day and slowly at night. So far, there has only been indirect evidence connecting the molecular feedback loop and SCN electrical activity. This research plan proposes a unique strategy that combines electrophysiology, real-time clock gene expression imaging, and the optogenetic manipulation of firing rate to elucidate the link between gene expression and firing rate rhythms in the SCN. Specifically, electrophysiological recording will be combined with real-time clock gene expression imaging in a novel transgenic mouse line (Per1:GFP mice) in which fluorescence is a readout of transcriptional activation of the core clock gene Per1 to determine the inherent phase relationship between firing rate and Per1 promoter activity. These techniques will also be used in animals in which Per1 is knocked out or overexpressed to investigate whether Per1 itself is a functional link between the molecular clock and electrical activity rhythms. Conversely, the influence of firing rate rhythms on circadian gene expression will be examined by using a combination of SCN-specific optogenetic manipulation of firing rate and time-lapse confocal imaging of clock gene expression in Per1: GFP mice expressing SCN-specific light-gated ion channels. These techniques will be used to determine how increasing, decreasing, or eliminating firing rate rhythms alter gene expression rhythms in the SCN. This research plan will ultimately help elucidate the relationship between SCN gene expression and electrical activity rhythms, which will improve our understanding of the interplay of essential circadian clock components whose dysfunction can negatively impact human health.

描述（由申请人提供）：了解神经系统中基因表达与电活动之间的相互作用是神经科学中的基本问题，对突触可塑性和神经发育等区域产生广泛影响。研究这种相互作用的一个有用的模型系统是大脑的生物钟，即核上核（SCN）。 SCN产生内源性分子和电昼夜节律，共同调节了许多生理过程。破坏的昼夜节律有可能影响一系列人类健康状况，例如睡眠和代谢疾病以及自闭症和抑郁症等神经精神疾病。为了了解昼夜节律成分的失调可能导致疾病，首先有必要了解它们如何在健康的大脑中工作。昼夜节律神经生物学中的一个关键问题是SCN的分子和电节律如何相互作用以形成连贯的起搏器。 SCN神经元是自动振荡器，每天具有涉及核心时钟基因PER1/2，CRY1/2，BMAL1和时钟的每日分子转录反馈回路。这些神经元可以自发发射动作电位，重要的是，可以调节其发射率，使它们白天快速发射，晚上缓慢发射。到目前为止，只有连接分子反馈回路和SCN电活动的间接证据。该研究计划提出了一种独特的策略，该策略结合了电生理学，实时时钟基因表达成像以及对发射速率的光遗传操作，以阐明SCN中基因表达与触发速率节奏之间的联系。具体而言，电生理记录将与新型的转基因小鼠系（PER1：GFP小鼠）中的实时时钟基因表达成像结合在一起，其中荧光是核心时钟基因转录激活的读数，以确定触发之间的固有相位关系速率和PER1启动子活性。这些技术也将用于将PER1撞倒或过表达的动物中，以研究PER1本身是否是分子时钟和电活动节奏之间的功能联系。相反，发射速率节奏对昼夜节律的影响 通过使用SCN特异性的光遗传学操纵和表达SCN特异性光门控离子通道的GFP小鼠中时钟基因表达的延时共聚焦成像的组合，将检查表达。这些技术将用于确定如何增加，减少或消除发射速率节奏改变SCN中基因表达节奏。该研究计划最终将有助于阐明SCN基因表达与电活动节奏之间的关系，这将提高我们对基本昼夜节律时钟组件的相互作用的理解，这些昼夜节律的功能障碍可能会对人类健康产生负面影响。