Nano-Scale Processes of Dendrogenesis

描述（由申请人提供）：神经系统的正确连接需要内在和外在信号的相互作用，这些信号决定了神经突的发育、结构和功能。虽然轴突的发育相对来说已经被很好地理解了，但对形成树突的力，尤其是装饰发育中的树突轴的纳米级丝状伪足的力却知之甚少。在脑回路布线过程中，哪些因素影响树突丝状足？丝状足对树突棘的形成、突触信息处理和可塑性有贡献吗？我们假设底物结合梯度中的化学线索通过纳米尺度的变化指导树突形态发生和成熟，将侧枝丝状足转变为棘。我们将在最近成功的基础上，在精细的微流体环境中以非常低的密度培养早期出生后大鼠的海马神经元。该R21提案以神经科学为中心，与材料科学相结合，创造和利用复杂的梯度化学领域——嵌入纳米级设计规则，并能够用特定的固定和扩散因子在培养中印记神经元的物理环境。这些实验能力由最先进的微流体系统提供，该系统利用各种物理行为来驱动设备内的程序化化学时间剖面。具体目标是：1)表征响应生物活性分子二维表面梯度的侧枝丝形行为，2)在这些发现的基础上构建3D梯度环境，促进丝形分化并使对弥漫性刺激的反应成为可能。模型为产后早期大鼠海马神经元和EGFP-actin转基因小鼠。我们寻求发现影响心理健康，神经修复和功能恢复的新颖见解，解决方案和应用。由于许多无法治愈的疾病（精神分裂症、抑郁症、帕金森氏症和阿尔茨海默病）造成巨大的经济成本，并将随着我们人口的老龄化而增加，因此对脑部疾病和治疗损害的顽固态度日益引起关注。神经系统的正常连接需要影响神经突发育、结构和功能的内在和外在信号的相互作用。本研究旨在通过将神经科学与材料科学相结合，在纳米级物理环境中创建和利用嵌入纳米级设计特征的复杂梯度化学场，了解纳米级丝状伪足在海马树突发生和脊柱形成中的作用。这种创新的方法使我们能够发现正常树突棘形成的新见解，这将为影响心理健康、神经修复和功能恢复提供新的策略、解决方案和应用，随着许多无法治愈的疾病（精神分裂症、抑郁症、帕金森病和阿尔茨海默病）带来巨大的经济成本，并将随着人口老龄化而增加，这些疾病越来越受到关注。

DESCRIPTION (provided by applicant): Proper wiring of the nervous system requires interplay of intrinsic and extrinsic signals that shape neurite development, architecture and function. Whereas axonal development is relatively well understood, less is known of the forces that shape dendrites, especially the nano-scale filopodia that decorate developing dendritic shafts. What factors influence dendritic filopodia during wiring of brain circuits? Do filopodia contribute to formation of dendritic spines, sites of synaptic information processing and plasticity? We hypothesize that chemical cues in substrate-bound gradients instruct dendrite morphogenesis and maturation via nanometer-scale changes that transform collateral filopodia into spines. We will build upon our recent success in culturing hippocampal neurons from early post-natal rat at very low densities in refined microfluidic environments. Centered in neuroscience, this R21 proposal bridges with materials science to create and exploit complex gradient chemical fields-ones embedding nanometer scale design rules and capable of imprinting the physical environments of neurons in culture with specific immobilized and diffusive factors. These experimental competencies are provided by state-of-the-art microfluidic systems that exploit a variety of physical behaviors to actuate programmed chemo-temporal profiles within the device. Specific aims are to: 1) characterize collateral filopodial behavior in response to 2D surface gradients of bioactive molecules, and 2) build upon these findings to construct 3D gradient environments that encourage filopodial differentiation and enable responses to diffusive stimuli. Models are hippocampal neurons of early post-natal rat and EGFP-actin transgenic mouse. We seek to discover novel insights, solutions and applications that impact mental health, neural repair and restoration of function. The intransigence of brain disorders and damage to treatment is of rising concern as many incurable conditions (schizophrenia, depression, Parkinson's and Alzheimer's disease) have huge economic costs and will increase with the aging of our population. PUBLIC HEALTH RELEVANCE: Nano-scale Processes of Dendrogenesis Proper wiring of the nervous system requires interplay of intrinsic and extrinsic signals that shape neurite development, architecture and function. This proposal seeks to understand the role of nano-scale filopodia in hippocampal dendrogenesis and spine formation by bridging neuroscience with materials science to create and exploit complex gradient chemical fields embedding nanometer-scale design features in nanoliter physical environments. This innovative approach positions us to discover novel insights for normal dendritic spine formation that will offer new strategies, solutions and applications that impact mental health, neural repair and restoration of function, which are of rising concern as many incurable conditions (schizophrenia, depression, Parkinson's and Alzheimer's disease) have huge economic costs and will increase with the aging of our population.