High-Throughput Analysis of Synaptic Diversity and Plasticity in Mouse Barrel Cor

描述(由申请人提供)： 新皮质微电路内连接的可塑性被认为是知觉学习和记忆的底物。小鼠须桶皮质因其优越的感觉和运动外周，以及其柱状结构的显着性和可达性，为新皮质可塑性的研究提供了许多独特的实验优势，这与啮齿动物和其他哺乳动物的新皮质的所有其他区域的结构高度相似。尤其是老鼠，因为它的体积小，而且可以获得越来越强大的遗传学工具，所以在成像研究中具有特殊的优势。目前，人们普遍预计，在未来几年内，对小鼠桶状皮质可塑性的研究将为全面了解健康和疾病中新皮质的学习和记忆机制提供最有希望的细胞和分子途径之一。阵列断层摄影术(ATOM)(Micheva和Smith 2007)是史密斯实验室开发的一项突破性的新成像技术，它首次允许在单个突触水平上高通量分析组织的分子结构。这种高通量的单突触分析能力提供了一个前所未有的机会，可以在全面和全景的范围内，以远远超过以往实验方法的详细程度和定量可靠性来测量新皮质突触的变化。我们将使用高通量原子来探索改变感觉刺激对小鼠胡须桶突触微电路的修改，识别最容易受到这种修改的特定突触群体，并表征突触蛋白质组成和结构的相应变化。这一关于单个突触分子结构变化的独特新视角有望为许多其他实验室正在进行的胡须桶可塑性体内研究提供非常有价值的补充。具体目标1：确定不同突触群体在桶状柱内的层状分布，并评估这种突触结构在柱和动物之间的可变性。具体目标2：描述长期主须刺激对桶状柱微电路内不同突触群体的层状分布的影响。具体目标3：比较不同突触群体在第4层棘状星状细胞和第5层锥体细胞上的可塑性。 公共卫生相关性： 大脑皮层的微电路是哺乳动物大脑所有高级功能的基础，包括感知、决策、学习和记忆。我们将使用阵列断层摄影术(Micheva和Smith 2007)，这是一种突破性的高分辨率、高通量成像技术，来全面绘制小鼠大脑特定微回路-体感桶柱内突触种群的分布。我们将揭示的电路结构原理不仅对于理解新大脑皮层的正常运行至关重要，而且还允许我们理解和预测这些电路如何适应不断变化的感觉环境或受到神经疾病的破坏。

DESCRIPTION (provided by applicant): Plasticity of connections within the neocortical microcircuit is thought to be the substrate for perceptual learning and memory. Mouse whisker barrel cortex offers many unique experimental advantages for the study of neocortical plasticity because of an advantageous sensory and motor periphery and because of the obviousness and accessibility of its columnar architecture, which is highly similar to the architecture of all other regions of neocortex in rodents and other mammals. The mouse in particular offers special advantages for imaging studies because of its small size and the availability of increasingly powerful genetics tools. It is now widely expected that work on the plasticity of mouse barrel cortex will provide for the next few years one of the most promising avenues toward a general cellular and molecular understanding of neocortical learning and memory mechanisms in health and disease. Array tomography (ATom) (Micheva and Smith 2007) is a groundbreaking new imaging technique developed by the Smith lab, which for the first time allows high-throughput analysis of the molecular architecture of tissue at the single-synapse level. This capacity for high- throughput single-synapse analysis provides an unprecedented opportunity to measure neocortical synaptic changes on a comprehensive and panoramic scale and at a level of detail and quantitative reliability far beyond previous experimental approaches. We will use high- throughput ATom to explore the modification of the synaptic microcircuitry of the mouse whisker barrel by altered sensory stimulation, identify specific synapse populations most subject to such modification and characterize corresponding changes in synapse protein composition and structure. This unique new perspective on changes in the molecular architectures of individual synapses is expected to provide an extraordinarily valuable complement to in vivo studies of whisker barrel plasticity being carried out in many other laboratories. Specific Aim 1: To define the laminar distributions of distinct synaptic populations within a barrel column and assess the variability of this synaptic architecture between columns and animals. Specific Aim 2: To characterize the effect of long term principal whisker stimulation on the laminar distributions of distinct synapse populations within the barrel column microcircuit. Specific Aim 3: To compare the plasticity of distinct populations of synapses onto layer 4 spiny stellate cells and layer 5 pyramidal cells. PUBLIC HEALTH RELEVANCE: The microcircuitry of the cerebral neocortex underlies all the higher functions of the mammalian brain, including perception, decision making, learning and memory. We will use array tomography (Micheva and Smith 2007), a groundbreaking high-resolution, high-throughput imaging technique, to comprehensively map the distribution of synaptic populations within a specific microcircuit of the mouse brain - the somatosensory barrel column. The principles of circuit architecture we will uncover are critical not only for understanding the normal operation of the neocortex, but also allow us to comprehend and predict how these circuits adapt themselves to changing sensory environments or are sabotaged by neurological disease.