A Picture is Worth 1000 Calories: The Neuroimaging of Obesity

一张照片值 1000 卡路里：肥胖的神经影像学

• 批准号: 8646598
• 负责人: KRISTEN ECKSTRAND
• 金额: $ 2.69万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-10 至 2015-09-09
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8646598
• 关键词: Animals; Area; Behavior; Behavioral; Binding; Body Weight; Body Weight decreased; Brain; Calories; Cardiovascular Diseases; Cause of Death; Cell membrane; Chronic Disease; Clinical Research; Complex; Corpus striatum structure; Cues; Data; Degenerative polyarthritis; Development; Diabetes Mellitus; Diet; Disinhibition; Dopamine; Dopamine D2 Receptor; Dopamine Receptor; Dorsal; Down-Regulation; Eating; Endocrinology; Epidemic; Epinephrine; Feeding behaviors; Food; Functional Imaging; Functional disorder; Goals; Habits; Human; Hyperphagia; Image; Impairment; Individual; Insulin; Insulin Resistance; Interneurons; Knowledge; Lead; Ligands; Link; Malignant Neoplasms; Maps; Measurable; Measures; Mediating; Medical; Medication Management; Mentorship; Molecular; Neurosciences; Neurosecretory Systems; Nuclear; Obesity; Obesity associated disease; Overweight; Participant; Physicians; Physiology; Placebos; Positron-Emission Tomography; Prefrontal Cortex; Process; Public Health; Randomized; Regulation; Research; Research Personnel; Research Project Grants; Resources; Rewards; Risk; Risk Factors; Role; Scientist; Signal Transduction; Surface; Synapses; System; Training; Translating; Translational Research; Visit; Weight; Weight Gain; arm; bioimaging; blood oxygen level dependent; cognitive control; design; dopamine transporter; executive function; expectation; extracellular; follow-up; functional disability; insulin signaling; meetings; neural circuit; neuroimaging; neurotransmission; noradrenaline transporter; obesity treatment; patient oriented; peripheral blood; prevent; programs; public health relevance; response; reward circuitry; skills; trafficking

DESCRIPTION (provided by applicant): Obesity-associated disease is the fifth leading cause of death worldwide. Obesity is a major risk factor for the development of diabetes, cardiovascular disease, cancer and osteoarthritis. A growing body of animal and human studies implicates deregulation of central dopamine circuits in excessive feeding behavior in obesity. Neuroimaging studies of obese individuals reveal a BMI-dependent decrease in striatal dopamine receptor levels. Interestingly, insulin enhances the surface expression of the dopamine transporter (DAT) while inhibiting that of the nor epinephrine transporter (NET). Together these transporters tune extracellular dopamine levels in the striatum and cortex respectively, areas critically involved in reward, habits, and cognitive control. This suggests tha impaired central insulin signaling, such as has been observed in animals placed on an obesogenic diet could, by blunting striatal, and enhancing cortical dopamine clearance, result in functional impairments in systems mediating food acquisition and overconsumption. In this study, obese individuals with mild impaired insulin signaling, randomized to receive insulin or placebo, will undergo longitudinal nuclear and functional imaging to examine insulin's ability to normalize deregulated striatal and cortical dopamine neurotransmission in obesity. Further, the interaction between dopamine neurotransmission and the effects of insulin specifically on prefrontal cortical function of inhibitory control will be examined. The overarching aim of this study is to assess whether the resetting of central insulin tone will normalize the opposing cortical and striatal dopamine deregulation sub serving the feeding behavior that progressively leads to obesity. This applicant-designed project exploits and expands upon a larger ongoing investigator-initiated patient-oriented clinical study, providing the applicant the opportunity to engage in directly translational research spanning the fields of neuroscience, endocrinology, and biomedical imaging. The proposed research program provides mentorship and training in all of these areas from leading physician scientists and researchers, neuroscience and neuroimaging coursework, and renowned institutional resources for both biomedical imaging and diabetes research. The training plan integrates the core principles of medical and scientific knowledge surrounding the path physiology of neuroendocrine dysfunction in the clinical research setting with the aim of directly translating animal and human research. The training plan emphasizes the acquisition and development of skills required for advanced neuroimaging research, including didactic and extracurricular training in functional and molecular neuroimaging. The finding of whether exogenous insulin modulates dopamine neurotransmission and behavior in a way that is beneficial will ultimately inform the current treatment and management of the global obesity epidemic.

描述（由申请人提供）：肥胖相关疾病是全球第五大死亡原因。肥胖是糖尿病、心血管疾病、癌症和骨关节炎的主要危险因素。越来越多的动物和人类研究表明，肥胖患者过度进食行为中中枢多巴胺回路的失调。肥胖个体的神经影像学研究显示纹状体多巴胺受体水平的bmi依赖性下降。有趣的是，胰岛素增强了多巴胺转运蛋白（DAT）的表面表达，同时抑制了肾上腺素转运蛋白（NET）的表面表达。这些转运蛋白共同调节纹状体和皮层的细胞外多巴胺水平，这两个区域与奖励、习惯和认知控制密切相关。这表明中枢胰岛素信号的受损，如在致肥性饮食的动物中观察到的那样，可以通过钝化纹状体和增强皮质多巴胺清除，导致介导食物获取和过度消耗的系统的功能损伤。在这项研究中，胰岛素信号轻度受损的肥胖个体，随机接受胰岛素或安慰剂治疗，将接受纵向核成像和功能成像，以检查胰岛素在肥胖患者中调节纹状体和皮质多巴胺神经传递正常化的能力。此外，多巴胺神经传递和胰岛素对抑制控制的前额皮质功能的影响之间的相互作用将被检查。本研究的主要目的是评估中枢胰岛素张力的重置是否会使相反的皮层和纹状体多巴胺解除管制正常化，从而使进食行为逐渐导致肥胖。这个由申请人设计的项目利用并扩展了一个更大的正在进行的研究者发起的以患者为导向的临床研究，为申请人提供了直接参与神经科学、内分泌学和生物医学成像领域的转化研究的机会。拟议的研究计划提供所有这些领域的指导和培训，来自领先的内科科学家和研究人员，神经科学和神经成像课程，以及生物医学成像和糖尿病研究的知名机构资源。该培训计划将围绕神经内分泌功能障碍路径生理学的医学和科学知识的核心原则整合到临床研究环境中，目的是直接转化为动物和人类研究。培训计划强调高级神经影像学研究所需技能的获取和发展，包括功能和分子神经影像学的教学和课外培训。外源性胰岛素是否以一种有益的方式调节多巴胺神经传递和行为，这一发现将最终为当前全球肥胖流行的治疗和管理提供信息。