Identification and manipulation of the neural ensembles mediating sundowning in an Alzheimer's disease mouse model

阿尔茨海默病小鼠模型中介导日落的神经群的识别和操作

• 批准号: 10016163
• 负责人: Christine Ann Denny
• 金额: $ 20.25万
• 依托单位: NEW YORK STATE PSYCHIATRIC INSTITUTE DBA RESEARCH FOUNDATION FOR MENTAL HYGIENE, INC
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10016163
• 关键词: 4-Hydroxy-Tamoxifen; APP-PS1; Affect; Age; Age-Months; Agitation; Alzheimer' s Disease; Alzheimer' s disease pathology; Alzheimer' s disease patient; Anxiety; Behavior; Behavioral; Behavioral Assay; Biological Assay; Brain; Brain imaging; Brain region; Caregivers; Cells; Characteristics; Circadian Dysregulation; Circadian Rhythms; Data; Development; Exhibits; Exposure to; FOS Protein; FOS gene; Goals; Hour; Human; Hypothalamic structure; Image; Immediate-Early Genes; Impaired cognition; Impairment; Label; Lateral; Light; Measures; Mediating; Memory; Methods; Microscope; Modeling; Molecular; Motor Activity; Mouse Protein; Mus; Neurodegenerative Disorders; Neurofibrillary Tangles; Neurons; Patients; Phenotype; Play; Polysomnography; Property; Proteins; Research; Resolution; Role; Signal Transduction; Sleep; Sleep Wake Cycle; Sleep disturbances; Synapses; System; Testing; Time; Virus; Visualization; Work; anxiety-like behavior; anxious; awake; biological systems; body system; circadian; discrete time; experience; improved; in vivo; in vivo imaging; long term hospitalization; mouse model; network dysfunction; neural circuit; neural correlate; neural network; novel; optogenetics; relating to nervous system; suprachiasmatic nucleus

PROJECT SUMMARY / ABSTRACT Circadian rhythms are everywhere in living matter from protozoans to human beings. Every cell, organ, and biological system works on an endogenous 24-hour rhythm. However, in patients with Alzheimer's disease (AD), a neurodegenerative disorder affecting memory, this rhythm is dampened. In addition to cognitive decline, many AD patients (~50%) also exhibit agitation and increased anxiety in the evening or nocturnal hours, often referred to as sundowning. Here, we aim to dissect the neural circuitry underlying sleep disturbances, circadian rhythm abnormalities, and increased anxiety-like behavior representing sundowning and how it relates to cognitive decline and AD pathology. We will utilize behavioral assays, optogenetics, whole-brainmicroscopy, and in vivo Ca 2+ imaging. Our preliminary evidence suggests that AD mice exhibit increased anxiety-like (e.g., sundowning) behavior compared to control (Ctrl) mice immediately before their sleep cycle but not before their wake cycle. Therefore, in Aim 1A, we will use the PiezoSleep mouse behavioral tracking system to monitor sleep/wake cycles and circadian homecage locomotor activity in Ctrl and AD mice at different ages in order to better characterize AD mice throughout their wake/sleep cycle. We will also measure anxiety-like behavior at various points throughout their sleep/wake cycles. Using an activity- dependent tagging mouse, the ArcCreERT2 x enhanced yellow fluorescent protein (EYFP) mice crossed with the APP/PS1 (AD) model, we will then identify whole-brain neural ensembles and therefore, neural networks that contribute to sundowning in Aim 1B. This mouse line allows for the indelible labeling of cells expressing the immediate early gene (IEG) Arc/Arg3.1 and allows for a comparison between the cells that are activated during one experience and those that are activated during a second experience. Here, we will compare and contrast the neural ensembles within subjects that are active during anxiety-like behaviors prior to the sleep and wake cycles. In Aim 2A, after identifying which neuronal ensembles are altered during sundowning, we will use nVoke minimicroscopes from Inscopix, to image Ca2+ transients in freely moving AD x ArcCreERT2 mice, injected with a GCaMP6f virus, during the dark versus light cycle. Here, we will be able increase resolution and the time points at which we can correlate neural activity with increased anxiety-like (e.g., sundowning) behavior. In Aim 2B, we will then test the hypothesis that optogenetic modulation of these neural ensembles drives/inhibits sundowning behavior. The neural circuitry underlying sundowning has not yet been elucidated, but this project will inform us of novel brain regions and the neural circuitry affected by sundowning and how we can manipulate these systems to rescue this phenotype in AD.

项目总结/摘要 从原生动物到人类，生物体的生理节奏无处不在。每一个细胞，器官， 生物系统以内源性的24小时节律工作。然而，在阿尔茨海默病患者中， (AD)这种神经退行性疾病会影响记忆，这种节奏会受到抑制。除了认知 虽然AD的发病率下降，但许多AD患者（约50%）在晚上或夜间也表现出激越和焦虑增加 时间，通常被称为日落。在这里，我们的目标是剖析睡眠背后的神经回路 紊乱、昼夜节律异常和代表日落的焦虑样行为增加 以及它与认知能力下降和AD病理学的关系。我们将利用行为 分析， 光遗传学， 全脑显微镜和体内Ca 2+成像。我们的初步证据表明，AD小鼠表现出 增加的焦虑样（例如，日落）行为与对照组（Ctrl）小鼠相比， 睡眠周期，但不是在他们的觉醒周期之前。因此，在目标1A中，我们将使用PiezoSleep鼠标 行为跟踪系统，以监测睡眠/觉醒周期和昼夜回家运动活动， 为了更好地表征AD小鼠在其整个觉醒/睡眠周期中的特征，我们将 还测量了他们在睡眠/清醒周期中不同时间点的焦虑行为。利用一种活动- 依赖性标记小鼠，ArcCreERT 2 x增强型黄色荧光蛋白（EYFP）小鼠与 APP/PS1（AD）模型，然后我们将识别全脑神经系综，从而识别神经网络 导致目标1B中的日落。该小鼠系允许表达以下蛋白的细胞的不可磨灭的标记： 立即早期基因（IEG）Arc/Arg3.1，并允许在被激活的细胞之间进行比较 在第一次体验中被激活，在第二次体验中被激活。在这里，我们将比较和 对比受试者在睡眠前焦虑样行为期间活跃的神经集合， 唤醒周期在目标2A中，在确定了哪些神经元集合在日落过程中发生了改变后，我们 将使用来自Insopix的nVoke微型显微镜，在自由移动的AD x ArcCreERT 2中对Ca 2+瞬变进行成像 注射GCaMP 6 f病毒的小鼠，在黑暗与光明的循环中。在这里，我们将能够增加 分辨率和我们可以将神经活动与增加的焦虑样（例如， 日落）行为。在目标2B中，我们将检验这些神经元的光遗传学调节 集合驱动/抑制日落行为。导致日落的神经回路还没有被 阐明，但该项目将告知我们新的大脑区域和神经回路受日落影响 以及我们如何操纵这些系统来挽救AD中的这种表型。