Localized mRNAs in Synaptic Plasticity

描述(由申请人提供)： 这个项目的长期目标是了解长时间的、依赖转录的神经元可塑性能够以突触特异性的方式进行调节的机制。大量研究表明，突触中mRNAs的定位和翻译调控是学习相关突触可塑性过程中神经元基因表达的重要机制。我们将使用两个与学习相关的可塑性模型系统，培养的海兔感觉-运动突触和培养的小鼠海马神经元，以确定定位于突触的mRNAs群体，并研究这些mRNAs的定位和调节翻译的机制。具体目标如下：1)鉴定突触定位的mRNAs。本研究的目的是通过构建基因文库和进行基因芯片分析，以无偏见的方式鉴定海兔感觉神经突起和小鼠海马树突中存在的mRNAs群体。2)研究突触刺激对mRNA定位的影响。这些实验将检测突触刺激对培养的海马神经元、培养的小鼠海马神经元和成年小鼠海马神经元中mRNA定位的影响。3)研究突触形成对mRNA定位的影响。这些实验的目的是研究突触的形成如何改变培养的海兔神经元中的mRNA定位。4)研究突触定位的mRNAs在可塑性过程中的翻译调控和局部蛋白质合成的作用。这些实验的目的是确定突触刺激如何调节局部mRNAs的翻译，并使用基因特异性沉默(RNA干扰)来检测局部翻译在突触可塑性中的作用。这些研究应该阐明神经元中依赖活性的基因表达调控的潜在机制。此外，他们还应阐明局部翻译在突触可塑性中的作用。从更大的角度来看，它们可能会促进我们对大脑中涉及神经元可塑性的许多生理和病理现象的理解，包括学习和记忆以及学习和记忆改变的疾病。

DESCRIPTION (provided by applicant): The long-term goals of this project are to understand the mechanisms whereby long-lasting, transcription-dependent neuronal plasticity can be regulated in a synapse-specific manner. A number of studies have indicated that localization and regulated translation of mRNAs at synapses serves as an important mechanism of gene expression in neurons during learning-related synaptic plasticity. We will use two model systems of learning-related plasticity, cultured Aplysia sensory-motor synapses and cultured mouse hippocampal neurons, to identify the population of mRNAs that are localized to synapses, and to investigate the mechanisms underlying the localization and regulated translation of these mRNAs. The specific aims are as follows: 1) Identify synaptically localized mRNAs. This aim is directed toward identifying, in an unbiased manner, the population of mRNAs present in Aplysia sensory neurites and in mouse hippocampal dendrites, by cDNA library construction and microarray analysis. 2) Characterize the effect of synaptic stimulation on mRNA localization. These experiments will examine the effect of synaptic stimulation on mRNA localization in cultured Aplysia neurons, in cultured mouse hippocampal neurons, and in adult mouse hippocampus. 3) Characterize the effect of synapse formation on mRNA localization. The aim of these experiments is to study how synapse formation alters mRNA localization in cultured Aplysia neurons. 4) Investigate the translational regulation of synaptically localized mRNAs and the function of local protein synthesis during plasticity. The aim of these experiments is to determine how synaptic stimulation regulates translation of localized mRNAs and to use gene specific silencing (RNA interference) to examine the function of local translation in synaptic plasticity. These studies should elucidate mechanisms underlying activity-dependent regulation of gene expression in neurons. In addition, they should elucidate the function of local translation during synaptic plasticity. From a larger perspective, they are likely to advance our understanding of the many physiological and pathological phenomena in the brain involving neuronal plasticity, including learning and memory and diseases in which learning and memory is altered.