Lesion Induced Synaptic Plasticity

描述(改编自申请者摘要)：本项目的目标是 确定调节再生和神经退行性反应的机制 切断主要谷氨酸能神经元后齿状回颗粒细胞的变化 输入，穿孔剂路径(PP)。在这个模型中，精确的损伤是在 成年小鼠在不损害海马结构的情况下横断PP， 允许对病变诱导的突触可塑性进行高分辨率评估 (LISP)。正在测试的假设是一种亚致死的、兴奋毒性的机制 发生在PP横断后，导致短期和长期的跨神经元 颗粒细胞和颗粒细胞树突的重组。要达到 细胞和亚细胞分辨率的必要水平，即“分子 齿状回颗粒细胞和颗粒细胞树突的指纹图谱 已执行。这是利用单细胞扩增的反义(Arna)完成的。 扩增方法学与基因芯片技术相结合提供了一种 数百个基因(约220个)的广泛同时表达 定制阵列上的cDNA和高密度cDNA上的6500个cDNA 微阵列)，重点是检测谷氨酸受体的变化 (GIuR)基因表达。因此，对GluRs和其他基因的mRNAs的调控 谷氨酸神经传递的转录本被用作生物标记物 区分塑料发芽反应和神经退行性改变 这在病变的整个时间进程中都会发生。兴奋性毒性假说是 通过检查分娩后颗粒细胞的表达谱来挑战 兴奋性氨基酸拮抗剂在PP横断术前。此外，一个 颗粒细胞兴奋性毒性的分子指纹图谱由 提供红藻氨酸，以便直接与PP横切术进行比较。此应用程序 应用广泛的功能基因组学方法来确定 LISP的分子底物，并测试兴奋性毒性假说 在PP横断面之后。谷氨酸受体和其他相关转录本的变化 有助于确定LISP后细胞后遗症与 理解活性依赖的细胞和分子基础 在海马环路内的反应，也直接与 揭示突触和神经退行性变化的机制(S) 在患有各种神经退行性疾病的人的大脑中。因此， 这种具有良好特征的PP的细胞和分子新范式转变 体内横切模型可能有助于识别特定的转录本，以及 最终，导致跨神经元退行性变和 轴突切断后树突状重塑。

DESCRIPTION (Adapted from applicant's abstract): The goal of this project is to determine mechanisms that regulate regenerative and neurodegenerative responses in dentate gyms granule cells following axotomy of the principal glutamatergic input, the perforant path (PP). In this model, a precise lesion is performed in adult mice that transect the PP without damaging the hippocampal formation, allowing for a high-resolution assessment of lesion-induced synaptic plasticity (LISP). The hypothesis being tested is that a sublethal, excitotoxic mechanism occurs following PP transections leading to short- and long-term transneuronal reorganization of granule cells and granule cell dendrites. To attain the necessary level of cellular and subcellular resolution, a "molecular fingerprint" of dentate gyms granule cells as well as granule cell dendrites is performed. This is done using a single cell amplified antisense (aRNA) amplification methodology combined with cDNA array technology to provide an extensive, concurrent representation of hundreds of genes (approximately 220 cDNAs on custom-designed arrays and 6500 cDNAs on high-density cDNA microarrays), with emphasis on detecting alterations in glutamate receptor (GIuR) gene expression. Thus, the regulation of mRNAs for GluRs and other transcripts of glutamatneric neurotransmission is used as a biological marker to differentiate plastic sprouting responses from neurodegenerative changes that occurs across the time course of the lesion. The excitotoxic hypothesis is challenged by examining granule cell expression profiles following the delivery of excitatory amino acid antagonists prior to PP transections. Further, a molecular fingerprint of excitotoxicity in granule cells is performed by delivery of kainate for direct comparison to PP transections. This application applies a broad scale functional genomics approach for determining the molecular substrates underlying LISP, and tests the excitotoxic hypothesis following PP transections. Alterations in GluRs and other relevant transcripts that help to determine cellular sequelae following LISP are relevant to understanding the cellular and molecular underpinnings of activity-dependent responses within hippocampal circuits and are also directly relevant to uncovering the mechanism(s) underlying synaptic and neurodegenerative changes in the brains of humans with a variety of neurodegenerative disorders. Thus, this novel cellular and molecular paradigm shift of the well-characterized PP transection model in vivo may help to identify specific transcripts, and ultimately, proteins that are responsible for transneuronal degeneration and dendritic remodeling following axotomy.