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，这些信号形成神经突起的发育、结构和功能。虽然轴突的发育相对较好，但对形成树突的力量知之甚少，特别是装饰正在发育的树突轴的纳米级丝状足细胞。在大脑回路的连线过程中，哪些因素会影响树突状丝状足细胞？丝状伪足是否有助于树突棘、突触信息处理和可塑性的形成？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示树突的形态发生和成熟，将侧丝足细胞转化为棘突。我们将在我们最近的成功基础上，在精致的微流体环境中以非常低的密度培养出生后早期大鼠的海马神经元。以神经科学为中心，R21提案与材料科学建立了桥梁，以创建和利用复杂的梯度化学场-嵌入纳米级设计规则的场，并能够用特定的固定和扩散因素在培养中的神经元的物理环境中留下印记。这些实验能力是由最先进的微流控系统提供的，这些系统利用各种物理行为来激活设备内的编程化学-时间分布。具体目标是：1)表征侧支丝径行为对生物活性分子的2D表面梯度的响应，以及2)在这些发现的基础上构建3D梯度环境，鼓励丝径分化并使其能够对扩散刺激做出反应。模型为生后早期大鼠海马神经元和绿色荧光蛋白-肌动蛋白转基因小鼠。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氏症)都有巨大的经济成本，而且随着人口老龄化，这些疾病将会增加，因此大脑疾病的顽固和对治疗的损害越来越令人担忧。与公共健康相关：树突状细胞的纳米级过程需要神经系统的正确连接，需要形成神经突起发育、结构和功能的内在和外在信号的相互作用。这项提议试图通过将神经科学与材料科学联系起来，创建和开发复杂的梯度化学场，在纳升物理环境中嵌入纳米级设计特征，来了解纳米级丝状足细胞在海马树突形成和脊椎形成中的作用。这种创新的方法使我们能够发现对正常树突棘形成的新见解，这将提供影响心理健康、神经修复和功能恢复的新策略、解决方案和应用，随着许多不可治愈的疾病(精神分裂症、抑郁症、帕金森氏症和阿尔茨海默病)具有巨大的经济成本，并将随着人口老龄化而增加，这些问题日益受到关注。

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.