Micro-and nano-mechanical and chemical guidance of neurons

神经元的微纳米机械和化学引导

• 批准号: 7199402
• 负责人: CHRISTINE E SCHMIDT
• 金额: $ 18万
• 依托单位: UNIVERSITY OF TEXAS AT AUSTIN
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-15 至 2009-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7199402
• 关键词: Actins; Adhesives; Axon; Cells; Characteristics; Chemicals; Cues; Decision Making; Development; Devices; Embryo; Enzymes; Event; Fluorescence; Fluorescence Microscopy; Goals; Growth; Growth Cones; Growth Factor; Hippocampus (Brain); Image Analysis; Individual; Injury; Knowledge; Lasers; Ligands; Measures; Mechanics; Modeling; Monitor; Nerve; Nerve Growth Factor 1; Nerve Growth Factor Pathway; Nerve Growth Factors; Nerve Regeneration; Neurites; Neurons; Pattern; Probability; Process; Range; Rat-1; Rattus; Research; Research Personnel; Research Project Grants; Scheme; Shapes; Signal Transduction; Standards of Weights and Measures; Stimulus; System; Techniques; Testing; Therapeutic; Work; axon growth; axon guidance; axonal guidance; cell behavior; cell injury; cell type; design; desire; human NTN1 protein; insight; interest; nano; nanofabrication; netrin-1; neuronal cell body; novel; polymerization; programs; repaired; response; therapy design

DESCRIPTION (provided by applicant): The PIs propose to develop novel micro- and nano-fabricated systems that can be used to monitor the simultaneous and competing effects of physical and chemical guidance cues on cell behavior. In particular, this work will focus on understanding how different types of signals "compete" to give rise to axonal extension from neurons. Many groups have studied the impact of different factors individually or in combination, but no one, to our knowledge, has looked at competition between individual factors and combinations of factors. This information will shed insight into the effect of external signals on polarization events and axonal guidance mechanisms involved in development and nerve regeneration, and could potentially provide insight into the desirable characteristics for therapeutic systems to aid nerve repair. To test how different signals contribute to neurite extension, micro- and nano-fabrication techniques will be used to create unique patterned geometries that simultaneously, and yet independently, present the neuron with physical or mechanical cues (e.g., grooves, pillars) and chemical cues (e.g., growth factors, adhesive ligands). In particular, the competition between grooved substrates and immobilized nerve growth factor and netrin-1, and combinations of these stimuli, will be studied for both polarization (axon initiation) and axon elongation and steering responses. Three different device geometries will be fabricated: (1) a "parallel" geometry to test polarization and decisions made at the cell body in response to competition between two stimuli, (2) a "cross-shaped" pattern to test polarization and decisions made at the cell body in response to competition between three or more stimuli, and (3) a "branched" pattern to test axon guidance and decisions made at the growth cone in response to two or more stimuli. Rat embryonic hippocampal neurons will be precisely micropositioned on the devices such that they have equal probability of encountering each separate cue. This will allow the cells to make "decisions" between competing factors by either defining an axon or extending an existing axon toward a desired signal. Image analysis and fluorescence microscopy will be used to measure neurite elongation and monitor the presence of axonal and dendritic markers in response to each cue. The three different proposed devices will be fabricated and optimized as part of Specific Aim 1 and the effects of signal competition on polarization and axon steering in rat hippocampal neurons will be assessed in Specific Aims 2 and 3, respectively.

描述（由申请人提供）：PI建议开发新型微米和纳米制造系统，可用于监测物理和化学引导信号对细胞行为的同时和竞争影响。 特别是，这项工作将侧重于了解不同类型的信号如何“竞争”以引起神经元的轴突延伸。 许多团体已经研究了不同因素单独或组合的影响，但据我们所知，没有人研究过单个因素和因素组合之间的竞争。 这些信息将深入了解外部信号对极化事件的影响以及参与发育和神经再生的轴突引导机制，并可能提供对帮助神经修复的治疗系统所需特性的深入了解。 为了测试不同的信号如何促进神经突延伸，微米和纳米制造技术将用于创建独特的图案几何形状，同时但又独立地向神经元呈现物理或机械线索（例如凹槽、柱）和化学线索（例如生长因子、粘附配体）。 特别是，将研究凹槽基质与固定神经生长因子和 netrin-1 之间的竞争以及这些刺激的组合，以实现极化（轴突起始）以及轴突伸长和转向反应。 将制造三种不同的设备几何形状：（1）“平行”几何形状，用于测试极化和细胞体响应两种刺激之间的竞争而做出的决策；（2）“十字形”图案，用于测试极化和细胞体响应三种或更多刺激之间的竞争而做出的决策；（3）“分支”图案，用于测试轴突引导和生长锥响应两种或多种刺激而做出的决策。 大鼠胚胎海马神经元将被精确地微定位在设备上，以便它们遇到每个单独提示的概率相同。 这将允许细胞通过定义轴突或将现有轴突延伸至所需信号来在竞争因素之间做出“决定”。 图像分析和荧光显微镜将用于测量神经突伸长，并监测响应每个提示的轴突和树突标记的存在。 三种不同的拟议设备将作为特定目标 1 的一部分进行制造和优化，信号竞争对大鼠海马神经元极化和轴突转向的影响将分别在特定目标 2 和 3 中评估。