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: 6420888
• 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 2003-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6420888
• 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(申请人提供)：维持正常血糖至关重要 因为葡萄糖是唯一可以被大脑、视网膜、 和生发上皮的数量足以提供所需水平的 能量。由于神经组织中的碳水化合物储备有限，正常神经 细胞的功能依赖于持续的葡萄糖供应。位于以下位置的神经元 精选大脑部位，包括后脑孤束核/区域 后复合体(NTS/AP)，表现为电生理和/或基因组 对糖减少症的反应，表明这种底物的调节信号 燃料短缺源于这些选定的基因座。基本问题 关于确定被监测的代谢变量和 局部“传感器”细胞传递能量的分子机制 神经信号的干扰仍未解决。微束粒子感生 X射线发射光谱分析(PIXE)是目前唯一可用的研究 以ppm灵敏度提供多元素定量的技术， 空间分辨率低于单元格维度的高精度。这个 拟议的项目将开发可供使用的核微探针分析技术 通过建立神经解剖学和药理学方法在一本小说中 神经功能电解性指标的表征策略 中央代谢“感应器”部位的细胞群对 葡萄糖可利用性的体内操纵。微米级分辨率和扫描 微束的传输成像能力提供了一种可能性 细胞内离子浓度的定量空间成像 可以产生“葡萄糖敏感”的大脑部位。预计 创新的技术改进将使区域测绘成为可能， 细胞水平上，葡萄糖缺乏对离子跨膜通量的影响，例如 钠、钾、氯和钙，调节神经元膜电位和突触 开火。补体免疫细胞化学方法的建立 胞浆神经递质，核转录因子， 而逆行标记预计将产生关于 表型鉴定、基因组反应和神经解剖学 “葡萄糖感应器”神经元的连接性。这项研究将具有重要的意义 细胞与分子碱基连接的研究进展 神经元能量学与葡萄糖供应的动态平衡调节。