Single-Synapse Analysis of Neocortical Circuit Plasticity

描述（由申请人提供）：许多不同形式的突触可塑性被广泛认为是正常脑发育、成熟脑的稳态以及我们适应变化的环境和损伤以及学习的能力所必需的。然而，将特定已知形式的突触可塑性与行为相关的脑回路可塑性的特定形式或位点联系起来的信息相对较少。在我们探索记忆及其障碍的分子、突触和电路基础时，我们知识上的这一差距使我们无法有效地确定已知功能相关的突触。本实验将利用小鼠触须感觉系统的独特优势，探讨新皮层突触可塑性的基本机制。这项工作将应用一种强大的新的高分辨率蛋白质组成像方法，称为“阵列断层扫描”（AT），以测量单个突触水平上皮质突触群体的分子和结构特征。AT具有独特的能力来分辨天然回路组织环境中的单个突触，测量数十种不同的分子标记物（例如，不同的受体，转运蛋白，信号传导，支架和粘附蛋白）在每个突触，并以非常高的实验通量这样做。因此，AT可以确定非常大的群体中每个个体突触的高维分子特征，并基于这种分子特征区分特定的突触亚群。拟议的研究将开发和应用一种新的基于AT的筛选策略，以无偏见的方式搜索特定小鼠新皮层突触中发生的结构和分子变化的模式，以应对特定的感觉适应和关联条件反射程序。

DESCRIPTION (provided by applicant): Synaptic plasticity in many different forms is widely recognized as essential to normal brain development, to homeostasis of the mature brain, and to our abilities to adapt to changing environments and injury and to learn. There is relatively little information, however, to link particular known forms of synaptic plasticity to particular forms or sites of behaviorally relevant brain circuit plasticity. This gap in our knowledge prevents us from efficiently pinpointing synapses of known functional relevance as we explore the molecular, synaptic, and circuit bases of memory and its disorders. The experiments proposed here will exploit unique advantages of the mouse whisker sensory system to explore basic mechanisms of neocortical synaptic plasticity. The work will apply a powerful new high-resolution proteomic imaging method called "array tomography" (AT) to measure molecular and structural characteristics of cortical synapse populations at the level of individual synapses. AT has unique abilities to resolve individual synapses in native circuit tissue context, to measure dozens of distinctive molecular markers (e.g., diverse receptor, transporter, signaling, scaffolding and adhesion proteins) at each synapse, and to do so with very high experimental throughput. Thus, AT can determine a high dimensional molecular signature for each individual synapse in very large populations and differentiate specific synapse subpopulations on the basis of such molecular signatures. The proposed research will develop and apply a novel AT-based screening strategy to search in an unbiased fashion for patterns of structural and molecular change occurring in specific mouse neocortical synapses in reaction to specific sensory adaptation and associative conditioning procedures.