GLP1R neurons in the subfornical organ and integration of thirst and satiety cues

项目摘要 感官生物学的发现不仅塑造了我们的生活方式，而且对我们的生活产生了重要影响。 人体健康我的长期职业目标是更好地了解环境线索是如何被检测到的， 编码在外围，并与大脑沟通，以控制生理和行为的健康， 疾病我在本提案中描述的当前目标是研究GLP-1如何集中通信 与穹窿下器官一起控制水分摄入和体液平衡。维持体液平衡 对健康和疾病至关重要。高糖引起糖尿病患者循环渗透压升高引起烦渴 患者涉及胰高血糖素样肽1（GLP-1）的模拟或稳定的肠促胰岛素疗法提供了一种新的治疗方法。 2型糖尿病治疗策略。作为肠促胰岛素，GLP-1不仅控制胰岛素的释放和进食， 行为，而且还调节血压，钠的肾脏排泄和液体摄入，以协调促进 在饭后系统地消化。有趣的是，急性GLP-1给药可诱发干渴减退， 有效地减少了健康受试者和糖尿病患者的水消耗，这表明了一种替代方案， 减轻糖尿病患者烦渴策略在表达GLP受体的许多位点中- 1（GLP 1 R），穹窿下器官是控制水摄入和流体稳态的主要脑中心。我 中心假设是SFO GLP 1 R神经元在餐后整合饱腹感信号以控制液体摄入 通过特定的信号级联和中枢神经回路。我将通过三个具体的例子来验证这个假设。 目的：确定SFO GLP 1 R神经元刺激对液体摄入的影响（具体目的1）， GLP 1 R信号通路在这些细胞（具体目标2），并仔细检查其解剖和功能 具体目标3（Specific Aim 3）对于具体目标2所需的培训，我将继续受益匪浅 在我的导师Liberles教授的指导下，他在GPCR方面拥有令人难以置信的知识和理解力 信号通路为了实现具体目标1和3，我还需要扩大我的知识和技能， 包括小鼠行为和神经回路映射，例如立体定位脑外科手术、脑切片 电生理学和化学遗传学。这些知识和技能将通过与我的合作伙伴的培训获得， 导师布拉德福德·洛厄尔教授我从洛厄尔教授和他的实验室成员那里得到了巨大的指导， 过去，用Glp 1 r-ires-Cre小鼠代和脑立体定向注射。我会继续学习大脑 切片记录、狂犬病病毒追踪、通道视紫红质辅助电路映射（CRACM），以及 在洛厄尔教授的指导下进行了涉及DREADD的行为实验。特别是关于 SFO GLP 1 R神经元的解剖学追踪（具体目标3），需要非常广泛的脑知识 我将与Clifford Saper教授合作，他是神经解剖学专家40多年 体验.总之，这些研究将极大地扩展我们对GLP-1信号如何整合到 大脑协调控制生理学，并阐明基于GLP-1的药物设计。

Project Summary Discoveries made in sensory biology not only shape the way we live, but also have important repercussions for human health. My long-term career goal is to better understand how environmental cues are detected and encoded in the periphery, and communicated with the brain to control physiology and behavior in health and disease. My current objective described in this proposal is to investigate how GLP-1 communicates centrally with the subfornical organ to control water intake and body fluid homeostasis. Maintaining fluid homeostasis is crucial for health and disease. Elevation of circulatory osmolarity by high glucose causes polydipsia in diabetic patients. Incretin therapies that involve mimicry or stabilization of glucagon-like peptide 1 (GLP-1) provide a strategy for treatment of type 2 diabetes. As an incretin, GLP-1 not only controls insulin release and feeding behavior but also regulates blood pressure, renal excretion of sodium, and fluid intake to coordinately promote digestion at a systematic level after meal. Intriguingly, acute GLP-1 administration elicits hypodipsia and effectively reduces water consumption in both healthy subjects and diabetic patients, suggesting an alternative strategy for alleviating polydipsia in diabetic patients. Among the many sites that express the receptor for GLP- 1 (GLP1R), the subfornical organ is a major brain center that controls water intake and fluid homeostasis. My central hypothesis is that SFO GLP1R neurons integrate satiety signals after meal to control fluid intake through specific signaling cascades and central neural circuits. I will test this hypothesis through three specific aims: to determine the effect of SFO GLP1R neuron stimulation on fluid intake (Specific Aim 1), to decipher GLP1R signaling pathways in these cells (Specific Aim 2), and to scrutinize their anatomical and functional connectivity (Specific Aim 3). For the training necessary for Specific Aim 2, I will continue to greatly benefit from the guidance of my mentor Prof. Liberles, who has incredible knowledge and understanding in GPCR signaling pathways. To carry out Specific Aim 1 and 3, I will also need to broaden my knowledge and skills to include mouse behavior and neurocircuit mapping, such as stereotaxic brain surgeries, brain slice electrophysiology, and chemogenetics. Such knowledge and skills will be obtained from training with my co- mentor, Prof. Bradford Lowell. I have received tremendous guidance from Prof. Lowell and his lab members in the past, with generation of Glp1r-ires-Cre mice and brain stereotaxic injection. I will continue to learn brain slice recording, rabies virus-based tracing, channelrhodopsin-assisted circuit mapping (CRACM), and DREADD-involved behavioral experiments under the guidance of Prof. Lowell. Particularly regarding the anatomical tracing of SFO GLP1R neurons (Specific Aim 3) that requires very extensive knowledge of brain anatomy, I will collaborate with Prof. Clifford Saper, who is an expert in neuroanatomy more than 40 years experience. Together, these studies will greatly expand our knowledge on how GLP-1 signal is integrated in the brain to coordinately control physiology and shed light on GLP-1 based drug design.