Cross-frequency coupling of brain oscillations during human non-rapid-eye-movement (NREM) sleep: implications for cognitive function and memory consolidation.

人类非快速眼动 (NREM) 睡眠期间大脑振荡的交叉频率耦合：对认知功能和记忆巩固的影响。

• 批准号: RGPIN-2019-06990
• 负责人: DangVu, ThienThanh
• 金额: $ 2.91万
• 依托单位: Concordia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=739246
• 关键词: Cross; frequency; coupling; brain; oscillations

The sleeping brain is characterized by rhythmic oscillations of electrical activity produced by neurons, and detectable using electrodes placed on the scalp during an electroencephalogram (EEG). Increasing evidence suggests that these oscillations are important for memory consolidation processes taking place during sleep. The three major brain rhythms that have been investigated in that regard are : 1) slow oscillations, high-amplitude low-frequency rhythms that are predominant during the deepest stages of sleep (stage N3); 2) sleep spindles, waxing-and-waning faster oscillations that are mainly found during intermediate stages of sleep (stage N2); 3) gamma oscillations, the fastest rhythms among these three oscillations, and known to be important for the learning of new information. Past research studies have shown that these oscillations increase during sleep after learning, suggesting their involvement in the offline consolidation of memory traces. More recent evidence however suggests that beyond their individual occurrence it is their degree of interactions that relates to memory consolidation. In other words, the degree to which brain oscillations during sleep tend to occur together (e.g., slow oscillation with spindles, and spindles with gamma oscillations), a process called cross-frequency-coupling (CFC), seems to play a major role in how sleep benefits memory. The objective of the proposed research program is to investigate the interactions between slow oscillations, spindles and gamma rhythms during sleep and their relationship with the recall of information learnt prior to sleep. To achieve this objective, we will use EEG and brain imaging techniques (in particular functional magnetic resonance imaging, or fMRI) to study brain oscillations during sleep and relate them to memory performance during the daytime. We will perform these studies in groups of young and old healthy volunteers, in order to assess how aging affects CFC of brain oscillations during sleep and their relation to memory performances. We hypothesize that a higher CFC during sleep will be associated with a better recall of information after sleep, and that aging will be characterized by lower CFC during sleep in association with poorer memory performances. The current project will shed new light on the mechanisms and functions of sleep, particularly how sleep benefits memory consolidation processes, and how these mechanisms might be impaired with aging.

睡眠中的大脑的特征在于神经元产生的电活动的节律振荡，并且在脑电图（EEG）期间使用放置在头皮上的电极可检测到。越来越多的证据表明，这些振荡对睡眠期间发生的记忆巩固过程很重要。在这方面已经研究过的三种主要的脑节律是：1）缓慢振荡，高振幅低频节律，在睡眠的最深阶段占主导地位（N3阶段）; 2）睡眠纺锤波，主要在睡眠的中间阶段发现的快速波动（阶段N2）; 3）伽马振荡，这三种振荡中最快的节奏，并且已知对于新信息的学习是重要的。过去的研究表明，这些振荡在学习后的睡眠中会增加，这表明它们参与了记忆痕迹的离线巩固。然而，最近的证据表明，除了它们的个体发生之外，与记忆巩固有关的是它们的相互作用程度。换句话说，睡眠期间大脑振荡倾向于一起发生的程度（例如，慢振荡与纺锤波，和纺锤波与伽马振荡），一个过程称为交叉频率耦合（CFC），似乎发挥了重要作用，睡眠如何有利于记忆。拟议的研究计划的目的是调查慢振荡，纺锤波和伽马节律之间的相互作用，在睡眠和他们的关系与回忆的信息学习之前的睡眠。为了实现这一目标，我们将使用脑电图和脑成像技术（特别是功能性磁共振成像，或fMRI）来研究睡眠期间的脑振荡，并将其与白天的记忆表现联系起来。我们将在年轻和老年健康志愿者中进行这些研究，以评估衰老如何影响睡眠期间脑振荡的CFC及其与记忆表现的关系。我们假设，在睡眠期间较高的CFC将与睡眠后更好地回忆信息有关，而衰老的特征将是在睡眠期间较低的CFC与较差的记忆表现有关。目前的项目将揭示睡眠的机制和功能，特别是睡眠如何有利于记忆巩固过程，以及这些机制如何随着年龄的增长而受损。