Microscopic Quantitative Mapping Ion Flux in Rat Brain

大鼠脑中离子通量的显微定量绘图

• 批准号: 6620709
• 负责人: KAREN P BRISKI
• 金额: $ 9.95万
• 依托单位: UNIVERSITY OF LOUISIANA AT MONROE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2004-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6620709
• 关键词: X ray spectrometry; bioimaging /biomedical imaging; biological signal transduction; brain imaging /visualization /scanning; brain mapping; brain metabolism; calcium flux; chloride ion; glucose metabolism; immunocytochemistry; interdisciplinary collaboration; ion transport; laboratory rat; membrane channels; membrane potentials; method development; microspectrophotometry; neuroanatomy; neuronal transport; neurons; potassium; sodium

DESCRIPTION (provided by applicant): Maintenance of euglycemia is crucial because glucose is the sole nutrient that can be utilized by the brain, retina, and germinal epithelium in sufficient quantities to provide required levels of energy. Since carbohydrate reserves in neural tissue are limited, normal nerve cell function depends upon a continuous glucose supply. Neurons located in select brain sites, including the hindbrain nucleus tractus solitarius/area postrema complex (NTS/AP), exhibit electrophysiological and/or genomic responses to glucopenia, suggesting that regulatory signaling of this substrate fuel deficit originates within these select loci. Fundamental questions concerning the identification of monitored metabolic variables and the molecular mechanisms by which local "sensor" cells transduce energetic disturbances into neural signals remain unresolved. Microbeam particle-induced X-ray emission spectrometry (PIXE) is the sole available investigative technique that offers multi-elemental quantitation at ppm sensitivities, with high accuracy at spatial resolutions less than cellular dimensions. The proposed project will develop nuclear microprobe analytical techniques for use with established neuroanatomical and pharmacological approaches in a novel strategy to characterize electrolytic indices of neuronal function, in defined cell populations within central metabolic "sensor" sites, in response to in vivo manipulation of glucose availability. Micron-level resolution and scanning transmission imaging capabilities of microbeam offer the possibility that quantitative spatial imaging of intracellular ion concentrations in "glucose-sensitive" brain sites can be generated. It is anticipated that innovative technique refinements will permit regional mapping, at the single cell level, of effects of glucose deficits on transmembrane flux of ions, e.g. Na, K, Cl, and Ca, that regulate neuronal membrane potential and synaptic firing. Development of complementary immunocytochemical methods for demonstration of cytoplasmic neurotransmitters, nuclear transcription factors, and retrograde labels is expected to yield important new information on phenotypic identification, genomic responsiveness, and neuroanatomical connectivity of "glucose-sensor" neurons. This research will significantly advance current understanding of the cellular and molecular bases linking neuronal energetics with homeostatic regulation of glucose availability.

描述（由申请人提供）：维持免疫至关重要 因为葡萄糖是大脑，视网膜， 以及足够数量的生殖上皮，以提供所需水平的 能源由于神经组织中的碳水化合物储备有限，正常神经 细胞功能依赖于持续的葡萄糖供应。神经元位于 选择大脑部位，包括后脑孤束核/区域 postrema复合体（NTS/AP），表现出电生理和/或基因组学 对血糖减少的反应，表明这种底物的调节信号传导 燃料缺乏起源于这些选择位点。基本问题 关于监测的代谢变量的识别和 局部“感受器”细胞释放能量的分子机制 神经信号的干扰仍然没有得到解决。微束粒子诱导 X射线发射光谱法（PIXE）是唯一可用的研究 该技术提供ppm灵敏度的多元素定量， 在小于细胞尺寸的空间分辨率下的高精度。的 拟议的项目将开发核微探针分析技术， 在一个新的神经解剖学和药理学方法， 策略，以表征神经元功能的电解质指数，在定义 细胞群内的中央代谢“传感器”网站，在响应中， 葡萄糖利用率的体内操纵。高分辨率和扫描 微束的透射成像能力提供了这样的可能性， 细胞内离子浓度的定量空间成像 可以产生“葡萄糖敏感”脑部位。预计各国 创新的技术改进将使区域测绘成为可能， 细胞水平，葡萄糖缺乏对离子跨膜通量的影响，例如， Na、K、Cl和Ca，调节神经元膜电位和突触 击发互补免疫细胞化学方法的发展 细胞质神经递质，核转录因子， 逆行标记有望产生重要的新信息， 表型鉴定、基因组反应性和神经解剖学 “葡萄糖传感器”神经元的连接。这项研究将大大 推进当前对细胞和分子基础连接的理解 神经元能量学与葡萄糖可用性的稳态调节。