Efferent vagal modulation of neuropod cells in the small intestine

摘要 功能性胃肠道疾病是胃肠病中最常见的诊断。是这样的 疾病，如肠易激综合征或功能性消化不良，可通过改变的胃肠道敏感性和 能动性。虽然病理生理机制复杂，但一个保守的特征是大脑的双向改变- 本能的信号。因此，这些疾病被归类为脑-肠道相互作用障碍。而迷走神经是 大脑-肠道的主要环节，大脑如何传递调节胃肠道上皮感觉功能的神经信号 未知。我的长期职业目标是记录来自大脑的神经回路是如何改变大脑的 肠道感知营养的能力。在NIH指导性研究科学家发展的支持下 奖-K01，这项提案的目标是描绘一个大脑到肠道的神经回路，可以用来 改变肠道上皮细胞的感觉传导。这将通过三个目标来实现： 目的1.测定大鼠肠道感觉细胞释放的神经递质和激素 对兴奋性神经递质刺激的反应。一种体外有机类化合物和分选单细胞测试将是 用于测量培养物中的释放。这一目的将证明兴奋性神经递质可以 刺激肠内分泌细胞释放囊泡。 目的2.将迷走神经刺激与感觉上皮细胞钙成像和电生理学结合起来 评估迷走神经突触到肠道感觉细胞的功能连接。这一目标将 显示神经细胞增加近端感觉细胞兴奋性的功能连接 小肠。 目的3.利用逆行(突触后至突触前)狂犬病病毒和顺行(突触前至突触后)狂犬病病毒 突触)单纯疱疹病毒追踪脑干和肠道之间的单突触连接 感觉上皮细胞。这一目标将建立一张脑干如何连接的解剖图 神经足细胞。 识别连接大脑和肠道的功能神经回路将使我们能够理解 内脏高敏感性背后的机制。我们和我的指导团队一起设计了这个 该项目为我提供了必要的研究和专业培训，使我成为一名优秀的 感觉神经胃肠病学领域的独立研究员。

ABSTRACT Functional gastrointestinal (GI) diseases are the most common diagnoses in gastroenterology. Such disorders, like irritable bowel syndrome or functional dyspepsia, are recognized by altered GI sensitivity and motility. Though the pathophysiology is complex, a conserved feature is the bidirectional alteration in brain- gut signaling. Thus, these are classified as disorders of brain-gut interaction. While the vagus nerve is the main brain-gut link, how the brain relays neural signals that modulate GI epithelial sensory function is unknown. My long-term career goal is to document how neural circuits originating from the brain alter the gut’s ability to sense nutrients. With the support of the NIH Mentored Research Scientist Development Award — K01, the objective of this proposal is to delineate a brain-to-gut neural circuit that could be used to alter sensory transduction at the gut epithelium. This will be accomplished in three aims: Aim 1. Determine the neurotransmitters and hormones released by intestinal sensory cells in response to excitatory neurotransmitter stimulation. An in vitro organoid and sorted single cell assay will be used to measure release in culture. This aim will demonstrate that an excitatory neurotransmitter can stimulate vesicular release in enteroendocrine cells. Aim 2. Pair vagal stimulation with sensory epithelial cell calcium imaging and electrophysiology to evaluate the functional connectivity of vagal neurons synapsing onto intestinal sensory cells. This aim will demonstrate a functional connection where neurons increase the excitability of sensory cells in the proximal small intestine. Aim 3. Utilize both retrograde (post- to pre-synapse) rabies virus and anterograde (pre- to post- synapse) herpes simplex virus to trace a mono-synaptic connection between the brainstem and intestinal sensory epithelial cells. This aim will establish an anatomical map for how the brainstem is connected to neuropod cells. Identifying functional neural circuits connecting the brain and the gut will enable the understanding of the mechanisms behind visceral hypersensitivity. Together with my mentoring team, we have designed this project to provide me with the necessary research and professional training for me to excel as an independent investigator in the field of sensory neurogastroenterology.