Generation and propagation of transient neuronal assemblies in the mouse hippocampus

在传播神经元集合的一般主题中，我们将重点关注一个特定的模型系统，即海马锐波纹波复合物。这些网络活动模式涉及主要神经元的特定子集，同时通过海马形成传播。它们可能在陈述性或空间记忆巩固中发挥作用，表明参与的细胞是由先前的可塑性过程选择的。还可以推断，海马体中同时存在几种明显不同的组件。我们希望使用现代电生理和光遗传学技术来监测小鼠海马-内嗅切片中的繁殖组装。然后，我们想要应用现代分析算法，提出以下问题：i)在海马体中可以识别出多少个组装体？ii)下游装配是否完全由上游装配的先前活动模式决定？iii)我们能否通过重复激活已定义的神经元子集来诱导新的组装？定义的组件是否明确地反映在不同的场电位波形中？总之，我们的工作将阐明传播组件的稳定性和可塑性。我们将改进我们的方法，不仅仅是通过与联盟的其他成员交流记录和分析技术。最后，我们对场电位和单个神经元活动的综合分析将有助于开发高分辨率脑电图分析的新方法。

Within the general topic of propagating neuronal assemblies, we will focus on a specific model system, namely hipocampal sharp wave-ripple complexes. These patterns of network activity involve defined sub-sets of principal neurons while propagating through the hippocampal formation. They might play a role in declarative or spatial memory consolidation, indicating that participating cells are selected by previous processes of plasticity. It can also be inferred that several clearly distinct assemblies co-exist in the hippocampus. We want to use modern electrophysiological and optogenetic techniques to monitor propagating assemblies in mouse hippocampal-entorhinal slices. We then want to apply modern algorithms of analysis, asking the following questions: i) How many assemblies can be identified in the hippocampus? ii) Are downstream assemblies completely determined by preceding patterns of activity in upstream assemblies? iii) Can we induce new assemblies by repetitive activation of defined subsets of neurons? iv) Are defined assemblies unambiguously reflected in distinct field potential waveforms?Together, our work shall shed light on the stability and plasticity of propagating assemblies. We will refine our methods, not at least by exchanging techniques of recording and analysis with other members of the consortium. Finally, our combined analysis of field potentials and single-neuron activity will help to develop new approaches for high-resolution EEG analysis.