Deconstructing brainstem circuits for visceral senses

项目总结/摘要 严格控制代谢稳态的能力对于动物的生存至关重要。内感觉神经 一个系统监测器官的状态，提供反馈信号，使大脑能够保持体内平衡 通过执行行为和生理反应。例如，系统检测并编码 胃肠道信号发出在进餐期间摄取的食物的质量和数量以控制进食行为， 消化生理学和全身代谢。内部感觉系统的失调， 消化系统疾病会导致各种疾病，包括肥胖、糖尿病和厌食症。内部感觉 脑干中的网关，孤束核（NTS），接收来自胃肠的输入， 呼吸和心血管系统通过迷走神经和其他神经/体液途径。反过来， NTS投射到不同的高级大脑区域，以产生我们对饱腹感、饥饿感、恶心感 和内脏疼痛尽管内部感觉系统在健康和疾病中的重要性， 处理内脏信号来调节行为和生理的研究还远远不够。解开高度 相互连接的脑干神经元需要全面分析解剖，感觉编码， NTS网络的功能，以了解介导个人内脏感觉的电路组件。博士米切尔 在斯蒂芬·利伯勒斯的实验室里，我最初的博士后工作是破译身体暗示的感官表征， NTS。在这个提议中，目标是确定内部感觉信息在大脑中被处理后， NTS被分为下游大脑区域，以控制行为和生理的特定方面。一是 将研究NTS投射组织的神经解剖学逻辑（目标1）。第二，内脏 将使用NTS投射神经元的体内钙成像来确定由每个投射传递的线索 (Aim 2）。最后，将讨论NTS投射在控制行为和自主生理中的功能作用。 建立，重点是介导生理饱足的途径（目的3）。本提案中的研究 将在斯蒂芬·利伯勒斯博士的指导下进行，他是内脏感觉研究的先驱。 神经解剖学领域的领先科学家Clifford Saper博士说， 和布拉德福德洛厄尔博士和Eleftheria Maratos-Flier，神经控制的专家， 食欲和能量代谢。本研究将建立一个NTS投射神经元的功能图谱， 内脏感觉，为我们理解代谢背后的神经回路提供了见解 稳态和策略，以开发针对代谢和内脏感觉障碍的靶向治疗。

PROJECT SUMMARY/ABSTRACT The ability to tightly control metabolic homeostasis is critical for animal survival. The internal sensory nervous system monitors the status of organs, providing feedback signals that enable the brain to maintain homeostasis by executing behavioral and physiological responses. For example, the system detects and encodes gastrointestinal cues signaling the quality and quantity of food ingested during a meal to control feeding behavior, digestive physiology, and whole-body metabolism. Dysregulation of internal sensory systems that monitor the digestive system can lead to various diseases, including obesity, diabetes, and anorexia. The internal sensory gateway in the brainstem, the nucleus of the solitary tract (NTS), receives inputs from the gastrointestinal, respiratory, and cardiovascular systems through the vagus nerve and other neural/humoral pathways. In turn, the NTS projects to diverse higher-order brain regions to generate our perceptions of satiety, hunger, nausea, and visceral pain. Despite the importance of internal sensory systems in health and disease, how neural circuits process visceral signals to regulate behavior and physiology is vastly understudied. Disentangling the highly interconnected brainstem neurons requires a comprehensive analysis of the anatomy, sensory coding, and function of the NTS network to understand the circuit components that mediate individual visceral senses. In Dr. Stephen Liberles’ lab, my initial postdoctoral work deciphered the sensory representations of bodily cues in the NTS. In this proposal, the goal is to determine how internal sensory information, after being processed in the NTS, is sorted into downstream brain regions to control specific aspects of behavior and physiology. First, the neuroanatomical logic by which NTS projections are organized will be investigated (Aim 1). Second, visceral cues transmitted by each projection will be determined using in vivo calcium imaging of NTS projection neurons (Aim 2). Last, the functional roles of NTS projections in controlling behavior and autonomic physiology will be established, with the focus on pathways that mediate physiological satiation (Aim 3). Research in this proposal will be conducted under the guidance of Dr. Stephen Liberles, who pioneered the study of viscerosensory neurons in the vagus nerve using genetic approaches, Dr. Clifford Saper, a leading scientist in the neuroanatomy of the viscerosensory system, and Drs. Bradford Lowell and Eleftheria Maratos-Flier, experts in neural control of appetite and energy metabolism. This proposal will establish a functional atlas of NTS projection neurons in visceral senses, providing insights into our understanding of the neuro-circuitry underlying metabolic homeostasis and strategies to develop targeted treatments for metabolic and viscerosensory disorders.