Ethanol and Neuronal Development

描述（由申请人提供）：该项目的长期目标是确定乙醇诱导神经元发育变化的细胞机制，并评估这些变化在以酒精相关神经发育障碍（ARND）和胎儿酒精综合征（FAS）为特征的CMS异常病因学中的作用。发育过程中乙醇暴露的神经病理学特征包括海马有丝分裂后神经元形态发生改变和海马内电路异常，这被认为是导致视觉空间和记忆缺陷的原因。我们之前的研究结果表明，乙醇破坏了体外海马锥体神经元轴突的初始生长时间和随后的生长动力学，并重组了其生长锥中的微管和肌动蛋白细胞骨架。本项目通过分子和药理学方法以及活细胞的高时间分辨率相对比和共聚焦成像，对低密度胎鼠海马锥体神经元培养中这些效应的细胞机制进行了假设测试。实验旨在确定乙醇诱导的神经元生长过程的变化是否涉及通过小rho家族gtpase和/或钙信号的调节来改变信号，包括生长锥中自发的、调节生长的钙瞬变。体内实验将描述乙醇对发育中的大鼠海马轴突及其树突靶点的形态调节作用，其中细胞外生长调节信号的时空表达被保留。结果将确定调节轴突和树突生长的信号通路的改变是否是乙醇神经发育作用的关键方面，并将测试动物模型以进一步验证这些作用在体内的作用。这项工作将揭示乙醇诱导的神经元损伤的细胞机制，可能作为预防或治疗ARND和FAS的新治疗策略的靶点。

DESCRIPTION (provided by applicant): The long-term objective of this project is to identify cellular mechanisms underlying ethanol-induced changes in neuronal development, and to assess the role of these changes in the etiology of CMS abnormalities that characterize alcohol-related neurodevelopmental disorders (ARND) and fetal alcohol syndrome (FAS). Neuropathologic features of ethanol exposure during development include altered postmitotic neuron morphogenesis in the hippocampus and abnormal intrahippocampal circuitry, which are thought to contribute to visuospatial and memory deficits. Our previous findings suggest that ethanol disrupts the timing of initial outgrowth and subsequent growth dynamics of hippocampal pyramidal neuron axons in vitro and reorganizes the microtubule and actin cytoskeletons in their growth cones. This project tests hypotheses regarding the cellular mechanisms underlying these effects in low-density fetal rat hippocampal pyramidal neuron cultures using molecular and pharmcologic approaches and high temporal resolution phase contrast and confocal imaging of live cells. Experiments are designed to determine whether ethanol-induced changes in neuronal process outgrowth involves altered signaling through small Rho-family GTPases and/or modulation of calcium signaling, including spontaneous, growth-regulating calcium transients in the growth cone. In vivo experiments will describe ethanol's morphoregulatory effects on axons and their dendritic targets in the developing rat hippocampus, in which the spatiotemporal expression of extracellular growth- regulating signals are retained. Results will establish whether altered signaling pathways regulating axonal and dendritic growth are a key aspect of ethanol's neurodevelopmental effects and will test an animal model for future verification of these effects in vivo. This work will reveal cellular mechanisms of ethanol-induced neuronal damage that may serve as targets for new therapeutic strategies to prevent or treat ARND and FAS.