Mechanisms of activation of vagal afferent neurons

迷走神经传入神经元的激活机制

• 批准号: 7473149
• 负责人: STEVEN M SIMASKO
• 金额: $ 22.09万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-22 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7473149
• 关键词: Acute; Address; Adipocytes; Adult; Afferent Neurons; Attention; Calories; Cells; Chemicals; Cholecystokinin; Chronic; Condition; Data; Digestion; Eating; Electrophysiology (science); Equilibrium; Event; FOS gene; Fiber; Goals; Health; Homeostasis; Hormones; Image; Immunohistochemistry; In Situ; Individual; Infusion procedures; Ingestion; Investigation; Label; Leptin; Methods; Nature; Neurons; Nodose Ganglion; Nonesterified Fatty Acids; Nutrient; Peptides; Physiological; Population; Preparation; Process; Property; Publishing; Rattus; Reporting; Research Personnel; Sensory; Series; Signal Pathway; Signal Transduction; Site; Source; Stimulus; Testing; Therapeutic Intervention; Tissues; Tweens; Vagus nerve structure; Work; absorption; design; energy balance; gastrointestinal; gastrointestinal function; in vivo; insight; lipid metabolism; nerve supply; patch clamp; research study; response; tool

DESCRIPTION (provided by applicant): The long-term goals of this project are to define the sensitivity of vagal afferent neurons to stimuli that are important to the control of energy homeostasis and to determine the cellular mechanisms by which these stimuli activate this afferent signaling pathway. The investigations in this proposal will specifically focus on the mechanisms of activation and degree of interaction of cholecystokinin (CCK), leptin, and free fatty acids (FFA) on vagal afferent neurons. These substances were chosen because there is abundant evidence that CCK, leptin, and FFA each participates in the control of body energy balance, and evidence exists that there are systemic interaction between these substances. Published reports, as well as preliminary data presented in the proposal, indicate that subpopulations of vagal afferents are sensitive to CCK, leptin, and FFA. Preliminary results further indicate that there are important interactions between these substances in the activation of individual vagal afferent neurons. In this project experiments will concentrate primarily on vagal afferent neurons isolated from adult rat nodose ganglia. The neurons in this preparation retain most, if not all, of the properties ascribed to intact vagal afferent fibers in vivo. The use of this preparation enables the design of much more refined and tightly controlled electrical, chemical, and pharmacological investigations of neuronal responses than are possible in vivo. This preparation will be used to address three specific aims: 1) A combination of single cell Ca2+ imaging, retrograde labeling, and immunohistochemistry, will be utilized to establish the innervation targets of discrete vagal afferent populations sensitive to CCK, leptin, and FFA. 2) Pharmacological tools combined with patch clamp electrophysiology and Ca2+ imaging will be utilized to determine the cellular mechanisms by which CCK, leptin, and FFA activate vagal afferent neurons, and to determine the cellular mechanisms by which these individual stimuli interact at the level of the vagal afferent neuron. 3) The hypothesis that in addition to acute activation and interactive effects, leptin, CCK, and FFA also have chronic and enduring effects on the responsiveness of these neurons will be tested. The degree to which individual vagal afferent neurons respond to and integrate signals from these disparate processes largely remains unappreciated. The insights developed in this series of investigations will enable a better reconstruct of the systemic actions and interactions of these important regulatory signals. A better appreciation of this important signaling pathway will contribute to the understanding of energy homeostasis and GI function, and aid in the design of therapeutic interventions for better health.

描述（由申请人提供）：该项目的长期目标是定义迷走神经传入神经元对刺激的敏感性，这对于控制能量稳态至关重要，并确定这些刺激激活这种传入信号通路的细胞机制。该提案中的研究将特别关注迷走传入神经元上胆囊基蛋白（CCK），瘦素和游离脂肪酸（FFA）的激活和相互作用的机制。之所以选择这些物质，是因为有大量证据表明CCK，瘦素和FFA各自参与控制人体能量平衡的控制，并且有证据表明这些物质之间存在全身相互作用。提案中提出的已发表的报告以及初步数据表明，迷走神经传入的亚群对CCK，Leptin和FFA敏感。初步结果进一步表明，这些物质在激活单个迷走神经元的激活中存在重要的相互作用。在该项目中，实验将主要集中于从成年大鼠淋巴结神经节中分离出的迷走神经神经元。这种制剂中的神经元保留了大部分（如果不是全部）归因于体内迷走神经传入纤维的特性。这种制备的使用可以设计出对神经元反应的更精致和紧密控制的电气，化学和药理学研究，而不是体内的可能。该制剂将用于解决三个特定目的：1）将使用单细胞Ca2+成像，逆行标记和免疫组织化学的组合来建立对CCK，Leptin和FFA敏感的离散迷走神经传入群体的神经支配靶标。 2）将利用与斑块夹具电生理学和Ca2+成像结合的药理学工具来确定CCK，Leptin和FFA激活迷走神经传入神经元的细胞机制，并确定这些单个个体刺激在流失传入的神经神经元水平上相互作用的细胞机制。 3）假设除了急性激活和互动效应外，瘦素，CCK和FFA还将测试这些神经元反应性的慢性和持久影响。单个迷走神经传入神经元对这些不同过程的信号的响应和整合的程度在很大程度上没有批准。在这一系列研究中开发的见解将使这些重要监管信号的系统性作用和相互作用更好地重建。更好地理解这一重要的信号通路将有助于理解能量稳态和GI功能，并有助于设计治疗干预措施以改善健康。