DECIPHERING THE ORIGIN OF MAGNETITE IN HUMAN BRAIN TISSUE

破译人类脑组织中磁铁矿的起源

• 批准号: 470880236
• 负责人: Professor Dr. Stuart Alan Gilder
• 金额: --
• 依托单位: Sektion Geophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/470880236?language=en
• 关键词: DECIPHERING; ORIGIN; MAGNETITE; HUMAN; BRAIN

Animals from several phyla are thought to detect the magnetic field and use it to their advantage. The most compelling example comes from magnetotactic bacteria that contain single domain (ca. 40-200 nm) magnetite (Fe3O4) or greigite (Fe3S4) crystals, called magnetosomes. Magnetosomes are fixed within the cell that compel the bacteria to swim along magnetic field lines. Interestingly, human brain tissue contains magnetite crystals that have identical morphologies as those found in some magnetotactic bacteria. Our previous work showed a systematic distribution of single domain magnetite in seven dissected, entire post mortem human brains suggesting the body internally biomineralizes the iron oxide. Other studies have reported much smaller (< 40 nm, superparamagnetic) magnetite in human brain tissue and suggested the superparamagnetic magnetite originates from external sources. This proposal aims to determine the properties, concentrations and the origin of both single domain and superparamagnetic magnetite particles in the human brain. We wish to further test whether a difference exists in magnetic characteristics between formalin-fixed tissue and fresh-frozen tissue. We propose to apply unique magnetic methods that will map the relative grain size and chemical composition of the magnetite as well as determine the spatial orientation (anisotropy) of the magnetite crystals in human brains. Systematic distribution in magnetite grain size, magnetite chemistry and/or geometric construction (anisotropy) would constitute groundbreaking evidence to determine the origin of magnetite in the human brain. If the magnetite is indeed shown to have a biogenic origin, then understanding its function in subsequent research should lead to important advances in human brain studies. If environmental, then understanding how the particles enter and become stored in the brain and their reactivity in physiological conditions will likewise have a huge impact on future research.

人们认为来自几个门的动物可以检测到磁场并利用其优势。最引人注目的例子来自包含单个结构域（约40-200 nm）磁铁矿（Fe3O4）或Greigite（Fe3S4）晶体的磁性细菌，称为磁体。磁体被固定在细胞内，该细胞将细菌沿磁场线游泳。有趣的是，人脑组织中含有与某些磁性细菌相同形态的磁铁矿晶体。我们以前的工作表明，单个结构域磁铁矿在七个解剖的，整个尸体后的人类大脑中的系统分布，表明人体内部生物矿物质会使氧化铁化。其他研究报告说，人脑组织中的磁铁矿较小（<40 nm，超顺磁性），并提出超顺磁磁铁矿起源于外部来源。该建议旨在确定人脑中单个结构域和超磁磁铁矿颗粒的特性，浓度和起源。我们希望进一步测试福尔马林固定组织和新鲜液体组织之间的磁性特征是否存在差异。我们建议采用独特的磁方法，以绘制磁铁矿的相对晶粒尺寸和化学成分，并确定人类大脑中磁铁矿晶体的空间取向（各向异性）。磁铁矿尺寸，磁铁矿化学和/或几何结构（各向异性）的系统分布将构成开创性的证据，以确定人脑中磁铁矿的起源。如果确实证明了磁铁矿具有生物源，那么了解其在随后的研究中的功能应导致人脑研究的重要进展。如果环境，那么了解颗粒如何进入并存储在大脑中，并且它们在生理条件下的反应性也将对未来的研究产生巨大影响。