Analyses of the Distributed Representation of Associative-Learning in an Identified Circuit Using a Combination of Single-Cell Electrophysiology and Multicellular Voltage-Sensitive Dye Recordings

项目总结/摘要 虽然在阐明细胞、生物物理和分子生物学方面已经取得了重大进展， 学习和记忆的机制，更少的是知道记忆过程的方式， 嵌入在神经元网络中。本提案的总体目标是提供对设计原则的见解 在神经回路的复杂环境中控制记忆的实现。研究将集中 在一个相对复杂的电路中，操作性条件反射（QC）的体外模拟物， 到人群范围的细胞和生物物理分析。细胞内和细胞外 电生理技术、电压敏感染料（VSD）成像、降维分析，以及 计算建模将识别和表征非突触和突触可塑性的位点。此外该 该项目将研究可塑性位点在短期和长期记忆之间共享的程度。要求1 将使用细胞内记录技术来检查QC诱导的可塑性位点。OC的先前相关性 该模型系统被限制为增加的内在兴奋性或电突触的关键神经元中， 电路.我们最近的研究结果表明，QC也降低了抑制性突触的强度和兴奋性 神经回路中的关键神经元。目的1将检查其他主要候选人的QC诱导的突触和非突触 可塑性，这在介导行为中具有既定的作用。此外，我们将使用细胞内 技术来检查我们最近的VSD记录显示出QC诱导的电路区域 活动的变化。计算模型将评估基因座单方面或协同工作的方式 介导OC表型。Aim 2将使用细胞内记录、VSD成像和 降维方法，以扩大搜索的其他网站的QC诱导的可塑性和 搜索OC的低维“签名”。目标1和2的综合结果将提供一个 评估与OC相关的可塑性机制的范围，这在任何系统中都是前所未有的。一 另一个重要的问题将由目标3解决，它将决定在多大程度上， 记忆在长期记忆中持续存在，相反，哪些可塑性部位可能是长期记忆所独有的。 记忆本建议将有助于全面了解 存储器被编码在相对复杂的电路中，阐明了存储器编码的设计原理，并且 为更复杂系统的类似分析提供指导。

PROJECT SUMMARY/ABSTRACT Although significant advances have been made in elucidating the cellular, biophysical and molecular mechanisms of learning and memory, much less is known about the ways in which mnemonic processes are embedded in neuronal networks. The overall goal of this proposal is to provide insights into the design principles that govern the implementation of memories within the complex environment of a neural circuit. Studies will focus on an established in vitro analogue of operant conditioning (QC) in a relatively complex circuit, which is amenable to population-wide, cellular, and biophysical analyses. A combination of intra- and extracellular electrophysiological techniques, voltage-sensitive dye (VSD) imaging, dimensionality reduction analysis, and computational modeling will identify and characterize loci of non-synaptic and synaptic plasticity. In addition, the project will examine the extent to which plasticity loci are shared between short- and long-term memory. Aim 1 will use intracellular recording techniques to examine loci of QC-induced plasticity. Previous correlates of OC in this model system were restricted to increases in intrinsic excitability or electrical synapses of key neurons in the circuit. Our recent results indicate QC also decreases the strength of an inhibitory synapse and the excitability of a key neuron in the circuit. Aim 1 will examine other prime candidates of QC-induced synaptic and non-synaptic plasticity, which have an established role in mediating the behavior. In addition, we will use intracellular techniques to examine regions of the circuit that our recent VSD recordings have shown to exhibit QC-induced changes in activity. Computational modeling will assess the ways in which loci work unilaterally or synergistically to mediate the OC phenotype. Aim 2 will use a combination of intracellular recordings, VSD imaging, and dimensionality reduction approaches to expand the search for additional sites of QC-induced plasticity and search for low-dimensional 'signatures' of OC. The combined results from Aims 1 and 2 will provide for an assessment of the scope of plasticity mechanisms associated with OC that is unprecedented in any system. A further important question will be addressed by Aim 3, which will determine the extent to which sites for short-term memory persist during long-term memory and, conversely, which sites of plasticity may be unique to long-term memory. The present proposal will help develop a comprehensive understanding of the ways in which memories are encoded in a relatively complex circuit, elucidate design principles of memory encoding, and provide guidance for similar analyses in more complex systems.