Diet-Induced Plasticity of Proopiomelanocortin Neurons

饮食诱导的阿黑皮素原神经元的可塑性

• 批准号: 8457178
• 负责人: Aaron Jeffrey Mercer
• 金额: $ 4.92万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8457178
• 关键词: Ablation; Acute; Adenovirus Vector; Affect; Anatomy; Animal Model; Animals; Appetite Depressants; Atlases; Axon; Basal metabolic rate; Biological Neural Networks; Brain; Canine Adenoviruses; Cell Nucleus; Cells; Chronic; Confocal Microscopy; Dendrites; Development; Diet; Disease; Distal; DsRed; Electrophysiology (science); Energy Metabolism; Enhancers; Epidemic; Etiology; Exhibits; Fasting; Fatty acid glycerol esters; Feeding behaviors; Fiber; Frequencies; Gene Silencing; Genes; Goals; Health; Healthcare; Homeostasis; Hyperphagia; Hypothalamic structure; Image; Injection of therapeutic agent; Intake; Label; Length; Leptin; Location; Maintenance; Maps; Measures; Mediating; Membrane Potentials; Metabolic; Metabolic Diseases; Metabolism; Morphology; Mus; Nervous system structure; Neuraxis; Neurites; Neuronal Plasticity; Neurons; Nutritional status; Obesity; Organism; Patch-Clamp Techniques; Pharmacotherapy; Phenotype; Physiological; Physiology; Presynaptic Terminals; Pro-Opiomelanocortin; Reagent; Regulation; Reporter; Reporting; Rest; Role; Signal Transduction; Site; Slice; Structure; Structure of nucleus infundibularis hypothalami; Synapses; Synaptophysin; System; Techniques; Testing; Therapeutic; Transgenes; Transgenic Animals; Transgenic Mice; Transgenic Organisms; United States; Vertebral column; Viral; Virus; Weight Gain; Wheat Germ Agglutinins; adenovirus receptor; cohort; combat; density; energy balance; feeding; insight; melanocortin receptor; nerve supply; neural circuit; neurobiotin; neuroregulation; promoter; receptor; recombinase; relating to nervous system; research study; vector

DESCRIPTION (provided by applicant): Central proopiomelanocortin (POMC) neuron, a circuit that promotes anorectic feeding behavior and negative energy balance, is one of the best-defined neural networks regulating metabolic function. Nevertheless, the extent to which POMC neurons integrate these metabolic signals throughout the CNS remains unclear. POMC neurons reside in the mediobasal hypothalamus, but a distinct lack of cytological organization has made them relatively intractable to anatomical analysis. Likewise, it is well-established that changes in the feeding state of an organism can rewire hypothalamic circuits, but the effects of diet on POMC neural plasticity has not been directly examined. To complete the anatomical map of central POMC integration and examine the effects of diet-induced rewiring of hypothalamic circuits, we will utilize transgenic animal models, trans-synaptic viral tracing, and single cell electrophysiology techniques. In the first set of experiments, replication-deficient Cr-expressing canine adenovirus (CAV-Cre) vectors will be used to functionally re- activate neural-specific Pomc deficient mice with a LoxP-flanked neo cassette in the neural enhancer module of Pomc. Because CAV-Cre specifically infects receptors at the synaptic terminal, the number of re-activated POMC neurons will be dependent on the abundance of POMC innervations at a distal target site. To directly examine POMC morphology and physiology at the cellular level, we will use single cell patch clamp techniques to measure basal neural activity and simultaneously label cells with neurobiotin. These experiments will be followed by different diet paradigms, which will allow us to examine the effects of acute versus chronic changes in feeding on the morphology and synaptic activity of POMC neurons. Finally, we will synthesize the effects of diet on the POMC network by applying our feeding paradigms to transgenic Pomc-Cre mice expressing Cre- dependent fluorescent dendritic and axonal markers. These mice will allow us to study circuit-level changes in POMC innervations, and will allow us to reconstruct the central POMC network into a complete atlas. Taken together, deciphering the structure and function of central POMC neurons will lend insight into neural control of energy homeostasis, critical for combating the worldwide obesity epidemic. PUBLIC HEALTH RELEVANCE: Obesity and related metabolic complications constitute over $150 billion in healthcare spending annually; therefore it is imperative for both the health and economy of the United States to develop therapeutics to combat this epidemic. Central proopiomelanocortin neurons are well known for their role in anorectic feeding behavior and energy expenditure, but the anatomy and plasticity of this circuit remains unclear. To facilitate an understanding of how the nervous system regulates metabolism and expedite the development of obesity-related therapeutics, the objective of this proposal is to elucidate the ful anatomical map of the proopiomelanocortin network and to determine how changes in diet can affect proopiomelanocortin physiology.

描述(申请人提供)：中枢前阿片黑素皮质素(POMC)神经元，促进厌食行为和负能量平衡的回路，是最明确的神经网络之一，调节代谢功能。然而，POMC神经元将这些代谢信号整合到整个中枢神经系统的程度仍不清楚。POMC神经元存在于下丘脑的内侧基底，但明显缺乏细胞学组织，使它们相对难以进行解剖学分析。同样，生物体摄食状态的改变可以改变下丘脑的神经回路，这一点已经得到证实，但饮食对POMC神经可塑性的影响尚未得到直接检验。我们将利用转基因动物模型、跨突触病毒示踪和单细胞电生理学技术来完成中央POMC整合的解剖图谱，并检查饮食诱导的下丘脑回路重新布线的影响。在第一组实验中，复制缺陷铬表达犬腺病毒(CAV-CRE)载体将被用来在POMC的神经增强器模块中通过loxP侧翼的neo盒来功能性地重新激活神经特异性POMC缺陷小鼠。由于CAV-CRE特异性地感染突触末端的受体，重新激活的POMC神经元的数量将取决于远端靶部位POMC神经支配的丰富程度。为了在细胞水平上直接检测POMC的形态和生理，我们将使用单细胞膜片钳技术来测量基础神经活动，同时用神经生物素标记细胞。这些实验之后将有不同的饮食模式，这将使我们能够检查急性和慢性摄食变化对POMC神经元的形态和突触活动的影响。最后，我们将通过将我们的喂养范例应用于表达Cre依赖的荧光树突状和轴突标记的转基因POMC-Cre小鼠，来综合饮食对POMC网络的影响。这些小鼠将允许我们研究POMC神经支配的电路水平的变化，并将允许我们将POMC中央网络重建为完整的图谱。综上所述，破译中枢POMC神经元的结构和功能将有助于深入了解神经对能量稳态的控制，这对抗击全球肥胖流行病至关重要。 公共卫生相关性：肥胖症和相关的代谢并发症构成了每年超过1500亿美元的医疗支出；因此，美国的健康和经济都必须开发治疗方法来抗击这一流行病。中枢前阿片黑素皮质素原神经元在厌食行为和能量消耗中的作用是众所周知的，但该回路的解剖学和可塑性仍不清楚。为了便于了解神经系统如何调节新陈代谢，加速肥胖相关疗法的发展，本提案的目的是阐明原阿片黑皮质素网络的完整解剖图谱，并确定饮食变化如何影响原阿片黑皮质素的生理。