Lesion Induced Synaptic Plasticity

描述（改编自申请人的摘要）：本项目的目标是 确定调节再生和神经退行性反应的机制 在齿状回颗粒细胞中， 输入，穿孔路径（PP）。在这个模型中，精确的损伤是在 横切PP而不损伤海马结构的成年小鼠， 允许对损伤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性毒性机制 发生在PP横断后，导致短期和长期跨神经元 颗粒细胞和颗粒细胞树突的重组。达到 细胞和亚细胞分辨率的必要水平，一个“分子 齿状回颗粒细胞和颗粒细胞树突的“指纹”， 执行。这是使用单细胞扩增反义（aRNA） 扩增方法学与cDNA阵列技术相结合，以提供一种 广泛的，同时表示数百个基因（约220个 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 （GIuR）基因表达。因此，GluRs和其他基因的mRNA的调节 谷氨酸能神经传递的转录物被用作生物标记物 区分塑料发芽反应和神经退行性变化 发生在病变的整个时间过程中。兴奋毒性假说是 通过检查颗粒细胞表达谱的挑战， 的兴奋性氨基酸拮抗剂前PP横切。此外，A 颗粒细胞兴奋性毒性的分子指纹是通过 用于与PP横切直接比较的红藻氨酸盐递送。本申请 应用广泛的功能基因组学方法来确定 分子底物的LISP，并测试兴奋毒性假说 PP横切后。GluRs和其他相关转录物的改变 帮助确定LISP后的细胞后遗症， 了解活动依赖性的细胞和分子基础 海马回路内的反应，也直接相关， 揭示突触和神经退行性变化的潜在机制 在患有各种神经退行性疾病的人的大脑中。因此，在本发明中， 这种新颖的细胞和分子范式转移的良好表征PP 体内横切模型可能有助于鉴定特定的转录本， 最终，负责跨神经元变性的蛋白质 轴突切断后的树突重塑。

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.