Quiescent dependent memory consolidation: memory-trace replay during REM sleep

记忆对人类和其他动物来说是一项至关重要的大脑功能。我们的日常活动完全依赖于记忆。例如，当我们开车时，我们使用多种形式的记忆，包括目的地的记忆，当前位置的记忆（随着移动而不断更新），以及如何操作汽车的记忆。此外，由于我们的预期寿命越来越长，保持良好记忆力的能力变得越来越重要。因此，了解记忆是如何在大脑中编码和维持的，是神经科学的一个重要而具有挑战性的问题。为了解释记忆在大脑中的巩固，我提出了一个静止依赖记忆巩固理论：当运动输出和感觉输入都关闭时，记忆在睡眠期间得到巩固。睡眠的静止为记忆的巩固提供了一个宽松的环境。我使用多电极记录技术来记录行为动物在清醒和睡眠期间的多神经元大脑活动。我通过比较任务期间的活动（动物被训练来执行特定的行为任务）、任务前睡眠和任务后睡眠来研究大脑活动是如何通过睡眠被修改的，重点关注一种被称为记忆追踪再激活的现象，即行为诱导的多神经元模式在随后的睡眠中重复。此外，通过比较神经元活动的变化和任务表现的改善，我研究了睡眠有助于学习的机制。此外，还研究了快速眼动睡眠和非快速眼动睡眠对记忆巩固的不同贡献。我测试了一个假设，即快速眼动睡眠有助于一种特定形式的记忆，如运动技能学习（如如何开车），而非快速眼动睡眠有助于另一种形式的记忆，如空间学习（如识别位置）。这个研究项目的所有结果将为睡眠期间记忆巩固的过程提供一个深入的见解，从而有助于我们对睡眠之谜的理解。

Memory is a crucial brain function for humans and other animals. Our everyday activities are entirely dependent upon memory. For instance, when we drive a car, we use multiple forms of memory including memory of the destination, memory of the current location (which keeps updating with movement), and memory of how to operate a motor vehicle. In addition, the ability to maintain good memory becomes increasingly important because our life expectancy is getting longer. Understanding how memory is encoded and maintained in the brain is, therefore, an important and challenging problem of neuroscience. To explain the consolidation of memory in the brain, I propose a theory of Quiescent Dependent Memory Consolidation: Memory is consolidated during sleep when both motor output and sensory input are shut down. The quiescence of sleep provides a permissive environment for memory consolidation. I use multiple-electrode recording technology to record multi-neuronal brain activity in behaving animals, both during awake and sleeping periods. I investigate how brain activity is modified through sleep by comparing the activity during a task (animals are trained to perform a certain behavioural task), pre-task sleep and post-task sleep, focusing on a phenomenon called memory-trace reactivation whereby behaviourally induced multi-neuronal patterns are repeated during subsequent sleep. Additionally, by comparing the change in neuronal activity and the improvement of task performance, I investigate the mechanisms by which sleep contributes to learning. Furthermore, different contributions of REM and non-REM sleep to memory consolidation are also investigated. I test the hypothesis that REM sleep contributes to a specific form of memory such as motor-skill learning (e.g. how to drive a car), whereas non-REM sleep contributes to another form of memory such as spatial learning (e.g. recognizing location). All the results of this research program will provide an insight into the process of memory consolidation during sleep and, thus, will contribute to our understanding of the mystery of sleep.