Diet-Induced Plasticity of Proopiomelanocortin Neurons

饮食诱导的阿黑皮素原神经元的可塑性

基本信息

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
项目类别：
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

项目摘要

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（由申请人提供）：中枢原阿黑皮质素（POMC）神经元是一种促进厌食进食行为和负能量平衡的回路，是调节代谢功能的最佳定义的神经网络之一。然而，POMC 神经元在整个 CNS 中整合这些代谢信号的程度仍不清楚。 POMC 神经元位于下丘脑内侧基底层，但明显缺乏细胞学组织，使得它们相对难以进行解剖分析。同样，众所周知，生物体摄食状态的变化可以重新连接下丘脑回路，但饮食对 POMC 神经可塑性的影响尚未得到直接研究。为了完成中枢 POMC 整合的解剖图并检查饮食诱导的下丘脑回路重新布线的影响，我们将利用转基因动物模型、跨突触病毒追踪和单细胞电生理学技术。在第一组实验中，复制缺陷型 Cr 表达犬腺病毒 (CAV-Cre) 载体将用于在 Pomc 神经增强子模块中通过 LoxP 侧翼 Neo 盒对神经特异性 Pomc 缺陷小鼠进行功能性重新激活。由于 CAV-Cre 特异性感染突触末端的受体，因此重新激活的 POMC 神经元的数量将取决于远端目标部位 POMC 神经支配的丰度。为了在细胞水平上直接检查 POMC 形态和生理学，我们将使用单细胞膜片钳技术来测量基础神经活动，并同时用神经生物素标记细胞。这些实验之后将进行不同的饮食模式，这将使我们能够检查急性与慢性饮食变化对 POMC 神经元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 依赖性荧光树突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。这些小鼠将使我们能够研究 POMC 神经支配的回路水平变化，并使我们能够将中央 POMC 网络重建为完整的图谱。总而言之，破译中央 POMC 神经元的结构和功能将有助于深入了解能量稳态的神经控制，这对于对抗全球肥胖流行至关重要。公共卫生相关性：肥胖和相关代谢并发症每年构成超过 1500 亿美元的医疗保健支出；因此，美国的健康和经济都迫切需要开发抗击这一流行病的疗法。中枢原阿黑皮素神经元因其在厌食摄食行为和能量消耗中的作用而众所周知，但该回路的解剖结构和可塑性仍不清楚。为了促进了解神经系统如何调节新陈代谢并加快肥胖相关疗法的开发，该提案的目的是阐明阿片黑皮质素原网络的完整解剖图，并确定饮食的变化如何影响阿片黑皮质素原生理学。