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

描述（由申请人提供）： 新皮层微回路内连接的可塑性被认为是感知学习和记忆的基础。小鼠须桶皮质为新皮质可塑性的研究提供了许多独特的实验优势，因为它具有有利的感觉和运动外围，并且因为其柱状结构的明显性和可访问性，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。特别是小鼠，由于其体积小和日益强大的遗传学工具的可用性，为成像研究提供了特殊的优势。现在人们普遍预计，在未来几年内，对小鼠桶状皮层可塑性的研究将为健康和疾病中新皮层学习和记忆机制的一般细胞和分子理解提供最有前途的途径之一。 阵列断层扫描（ATom）（Micheva和Smith 2007）是由Smith实验室开发的一种开创性的新成像技术，首次允许在单突触水平上对组织的分子结构进行高通量分析。这种高通量单突触分析的能力提供了前所未有的机会，以全面和全景的规模，并在细节和定量可靠性远远超过以前的实验方法的水平上测量新皮层突触的变化。我们将使用高通量ATom来探索通过改变感觉刺激对小鼠须桶的突触微电路的修饰，鉴定最易受到这种修饰的特定突触群体，并表征突触蛋白组成和结构的相应变化。这种独特的新的角度在个别突触的分子结构的变化，预计将提供一个非常有价值的补充，在体内研究的须桶可塑性正在进行的许多其他实验室。具体目标1：确定不同突触群体在桶柱内的层状分布，并评估这种突触结构在柱和动物之间的变异性。具体目标二：描述长时程主须刺激对桶柱微电路内不同突触群的层状分布的影响。具体目标3：比较第4层棘状星状细胞和第5层锥体细胞上不同突触群体的可塑性。 公共卫生相关性： 大脑新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扫描（Micheva和Smith 2007），一种突破性的高分辨率，高通量成像技术，全面绘制小鼠大脑特定微回路-体感桶柱内突触群的分布。我们将揭示的电路结构的原理不仅对理解新皮层的正常运作至关重要，而且还使我们能够理解和预测这些电路如何适应不断变化的感觉环境或被神经系统疾病破坏。

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.