CAREER: Imaging Mechanisms of Dendritic Development in the Living Neuron

哺乳动物大脑中的神经细胞（神经元）通常具有精细的细胞延伸的复杂树状分支，称为树突状乔木，它接收来自其他神经元的化学活动信号。 像天线一样，树枝状乔木上分支的位置和数量组织了传入输入的模式，因此决定何时在何处形成分支是至关重要的。 这些树突的细胞内结构包括称为肌动蛋白和微管的细胞骨架成分，这些成分是动态的，随着时间的推移通过延长或收缩或稳定特定点的分支来改变树突结构。 目前还不清楚是什么机制决定了这些高度特异性的乔木在发育和生长过程中的模式。 为了解决这个问题，该项目结合了几项最新的技术进展，这些技术进展能够：1）显着加速大脑海马区培养神经元中的树突发育; 2）通过高分辨率显微镜延时成像跟踪活神经元中蛋白质和细胞器的表达和运输;以及3）使用新颖的创造性纳米纤维技术来产生图案化的基底，以提供细胞发育的外部线索。 这些实验将确定肌动蛋白和微管动力学的作用，以及外部线索（如细胞粘附分子和其他神经元传入接触的位置）对树突分支的影响。 研究结果将为神经发育的一个重要课题提供重大进展，其中基本信息仍然未知，跨学科方法将加强生物学和工程学之间的相互作用。 教育活动与研究的完美结合将对这所文科学院的研究经验产生重大影响，甚至对当地公立学校产生重大影响。

Nerve cells (neurons) in the mammalian brain often have elaborate treelike branching of fine cellular extensions called dendritic arbors, which receive the chemical signals of activity from other neurons. Like an antenna, the location and number of branches on a dendritic arbor organize the pattern of the afferent input, so the decision about where and when to form a branch is critical. The intracellular structures of these dendrites include cytoskeletal components called actin and microtubules, and these components are dynamic, changing the dendritic structure over time by elongation or retraction or stabilization of the branches at particular points. It remains unclear what the mechanisms are that determine the patterning of these often highly specific arbors during development and growth. To approach this question, this project combines several recent technical advances that give the ability to 1) accelerate dendritic development significantly in cultured neurons from the hippocampal region of the brain; 2) follow the expression and trafficking of proteins and organelles within the living neuron by high-resolution microscopic time-lapse imaging; and 3) to create patterned substrates, using novel creative nanofabrication techniques to provide external cues for cellular development. The experiments will determine the roles of actin and microtubule dynamics, and the influence of external cues such as cell adhesion molecules and location of afferent contacts from other neurons, on dendritic branching. Results will provide a major advance on an important topic of neural development where fundamental information is still unknown, and the interdisciplinary approach will enhance interactions between biology and engineering. The excellent integration of educational activities with the research will have a major impact on research experience in this liberal arts college, and even on the local public schools.