Delineating and testing a microcircuit model of parahippocampal phase precession

描绘和测试海马旁相位进动的微电路模型

• 批准号: 322164732
• 负责人: Professor Dr. Michael Brecht
• 金额: --
• 依托单位: Arbeitsgruppe Theoretical Neuroscience
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/322164732?language=en
• 关键词: Delineating; testing; microcircuit; model; parahippocampal

Throughout the hippocampal formation, the firing activity of place or grid cells and the EEG theta rhythm (~8Hz) are related: When an animal enters a cell´s firing field, the first spikes arrive at a late phase of the theta oscillation. As the animal traverses the field, the spikes in subsequent cycles of the theta oscillation arrive at earlier and earlier phases. Spikes "precess" throughout the place field. Phase precession is one of the most investigated topics in systems neuroscience and might be instrumental in matching the time scale of behavioral learning, which occurs in the range of seconds or more, to the time scales of synaptic plasticity, which are often in the range of milliseconds. Previous research on phase precession resulted in a rich description of the temporal discharge phenomenology of neurons and in numerous models of phase precession. Still the mechanism(s) underlying phase precession are unknown. We will try to solve this problem by analyzing layer 3 of the entorhinal cortex, where neurons show prominent phase precession. Previous attempts to explain phase precession suffered from four intertwined problems: (1) phase precession models are typically underconstrained, (2) most studies do not formulate precise microcircuit models, (3) models are therefore not strongly predictive, (4) models are typically not tested, i.e. they are experimentally inconsequential. The unique composition and the complementary expertise of our research consortium will allow us to overcome these problems: (i) Connectivity analysis and high-resolution recordings will delineate entorhinal microcircuits with unprecedented precision. (ii) These data will be funneled into a strongly predictive microcircuit model. (iii) Accordingly, this model can be tested in vitro and in vivo. Our approach will enable us to selectively interfere with phase precession and test its role in spatial memory formation.

在整个海马结构中，位置或网格细胞的放电活动和EEG θ节律（~8Hz）是相关的：当动物进入细胞的放电区时，第一个尖峰到达θ振荡的晚期。当动物穿过磁场时，θ振荡的后续周期中的尖峰到达越来越早的相位。在整个位置字段中，尖峰“旋进”。相位进动是系统神经科学中研究最多的主题之一，可能有助于将行为学习的时间尺度（发生在秒或更长的范围内）与突触可塑性的时间尺度（通常在毫秒范围内）相匹配。以往的研究相位进动导致了丰富的描述的时间放电现象的神经元和相位进动的许多模型。相位进动的机制仍然是未知的。我们将尝试通过分析内嗅皮层的第3层来解决这个问题，在那里神经元表现出显著的相位进动。先前解释相位进动的尝试遭受了四个相互交织的问题：（1）相位进动模型通常约束不足，（2）大多数研究没有制定精确的微电路模型，（3）模型因此没有强预测性，（4）模型通常没有测试，即它们在实验上是无关紧要的。我们的研究联盟的独特组成和互补的专业知识将使我们能够克服这些问题：（i）连接分析和高分辨率记录将以前所未有的精度描绘内嗅微电路。(ii)这些数据将被汇集到一个强预测微电路模型中。(iii)因此，该模型可以在体外和体内进行测试。我们的方法将使我们能够选择性地干扰相位进动，并测试其在空间记忆形成中的作用。