The role of grid cell replay in navigation and memory consolidation

网格单元重放在导航和记忆巩固中的作用

• 批准号: 1763798
• 金额: --
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1763798
• 关键词: role; grid; cell; replay; navigation

Experimental evidence links the hippocampus and related brain regions with memory for places and events. Investigations in animals provided a neural basis for these functions; neurons with spatially tuned receptive fields. The most widely recognized of which being hippocampal place cells and entorhinal grid cells, both of which appear to signal an animal's self-location. Questions remain. It is unclear how these neurons are engaged when an animal is planning routes to travel in the immediate future. Furthermore, it is known that hippocampal damage produces severe mnemonic deficits but that old memories are often spared, suggesting their content is duplicated in the brain; an effect known as consolidation. Again the role of place and grid cells in this process are unclear. None-the-less, a potential mechanism underlying both navigational planning and consolidation is replay; a phenomenon identified in place cells, during which the cells 'simulate' trajectories through the environment. We showed that grid cells are also recruited during replay, with their activity typically lagging behind place cells. This supports the notion of relay involvement in consolidation, suggesting the grid cells convey hippocampal information to the cortex.. We also proposed a computational model suggesting that grid cell replay may be a mechanism by which routes are calculated; a simple prediction being that replay should occur when animals make navigational choices. However, replay analyses are demanding and require large numbers of neurons to accurately decode the information content. The aims of this project are to use two photon microscopy to record replay in larger populations of grid cells than have previously been accessible, this will enable better quantification of the involvement of grid replay in navigation and consolidation. Secondarily it will enable us to distinguish the engagement of cells from different layers of the entorhinal cortex, which have distinct connectivity patterns with the hippocampus.

实验证据表明，海马体和相关的大脑区域与对地点和事件的记忆有关。对动物的研究为这些功能提供了神经基础;具有空间调谐感受野的神经元。其中最广为人知的是海马定位细胞和内嗅网格细胞，这两种细胞似乎都能发出动物自我定位的信号。问题依然存在。目前还不清楚当动物计划在不久的将来旅行的路线时，这些神经元是如何参与的。此外，海马损伤会导致严重的记忆缺陷，但旧的记忆通常不会被破坏，这表明它们的内容在大脑中被复制;这种效应被称为巩固。位置细胞和网格细胞在这个过程中的作用仍然不清楚。尽管如此，导航规划和整合的潜在机制是重放;在位置细胞中识别的现象，在此期间细胞“模拟”通过环境的轨迹。我们发现，网格细胞也在重放过程中被招募，它们的活动通常落后于位置细胞。这支持了中继参与巩固的概念，表明网格细胞将海马信息传递到皮层。我们还提出了一个计算模型，表明网格细胞重放可能是一种机制，通过它来计算路线;一个简单的预测是，重放应该发生在动物进行导航选择。然而，重放分析要求很高，需要大量的神经元来准确地解码信息内容。该项目的目的是使用双光子显微镜记录重放在更大的群体的网格细胞比以前已经访问，这将使更好的量化网格重放参与导航和巩固。其次，它将使我们能够区分来自内嗅皮层不同层的细胞的参与，内嗅皮层与海马体具有不同的连接模式。