Decoding sleeping brain activity: Integrating experiments and computational neuroscience to elucidate the cognitive benefit of sleep

解码睡眠大脑活动：结合实验和计算神经科学来阐明睡眠的认知益处

• 批准号: RGPIN-2020-06342
• 负责人: Tatsuno, Masami
• 金额: $ 2.4万
• 依托单位: University of Lethbridge
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=761422
• 关键词: Decoding; sleeping; brain; activity; Integrating

Various brain functions such as perception, learning and memory and decision making emerge from neural computations. Using electrophysiological and computational approaches, we have been specifically focusing on `learning and memory' because it provides the basis of other high-order cognitive functions. Memory is broadly categorized into explicit and implicit memories. Explicit memory is a type of memory that you can recall consciously and verbally describe (for example, the breakfast you had this morning). Implicit memory is a type of memory that you cannot recall consciously nor verbally describe (for example, the motor skill required to ride a bike). Two important questions regarding these memories are how they are represented in the brain and how/when they are consolidated in the neural circuits. A widely supported theory is that a group of anatomically/functionally connected neurons, called a `cell assembly', represents memory. It has been also proposed that consolidation of memory occurs in part during sleep. This memory function of sleep has been supported by experiments showing that behaviourally induced neural activity reactivates during sleep (memory reactivation) and that memory is modified by electrical stimulation during sleep. Although we have these general frameworks for memory and sleep, the term `cell assembly' lacks the stringent definition and we still do not understand how different types of memory are represented by cell assemblies. We do not know how cell assemblies are modified during sleep either. Furthermore, experiments in which memory was modified by electrical stimulation during sleep were challenged by recent negative results. Therefore, in this proposal, we will perform electrophysiological experiments to clarify the mixed experimental results on memory and electrical stimulation, develop a systematic cell assembly detection method to understand how explicit and implicit memories are represented, and develop a computational model to understand how sleep modifies neural circuits and hence memories. The outcomes of this proposal will highlight similarities and differences between explicit and implicit memory, provide better estimates of storage capacity, clarify the effect of electrical stimulation during sleep, and provide better mechanistic insights into how synaptic plasticity during sleep modifies neural activity. The work will also help improve brain-inspired technologies. For instance, deep learning may become more flexible and obtain better categorization ability by implementing memory function of sleep.

各种大脑功能，如感知、学习、记忆和决策，都是从神经计算中产生的。利用电生理学和计算方法，我们一直特别关注“学习和记忆”，因为它为其他高阶认知功能提供了基础。记忆大致分为外显记忆和内隐记忆。外显记忆是一种你可以有意识地回忆和口头描述的记忆（例如，你今天早上吃的早餐）。内隐记忆是一种你不能有意识地回忆或口头描述的记忆（例如，骑自行车所需的运动技能）。关于这些记忆的两个重要问题是，它们是如何在大脑中表现出来的，以及它们是如何/何时在神经回路中得到巩固的。一个被广泛支持的理论是，一组在解剖学上/功能上相互连接的神经元，被称为“细胞集合”，代表着记忆。也有人提出，记忆的巩固部分发生在睡眠期间。睡眠的这种记忆功能得到了实验的支持，实验表明，行为诱导的神经活动在睡眠期间重新激活（记忆再激活），记忆在睡眠期间被电刺激修改。尽管我们有这些记忆和睡眠的一般框架，但术语“细胞组合”缺乏严格的定义，我们仍然不明白不同类型的记忆是如何由细胞组合来表示的。我们也不知道在睡眠期间细胞组合是如何改变的。此外，通过睡眠时的电刺激来改变记忆的实验受到了最近负面结果的挑战。因此，在本提案中，我们将通过电生理实验来澄清记忆和电刺激的混合实验结果，开发一种系统的细胞组装检测方法来了解外显和内隐记忆是如何表征的，并开发一个计算模型来了解睡眠如何改变神经回路从而改变记忆。这一建议的结果将突出外显记忆和内隐记忆之间的异同，提供更好的存储容量估计，阐明睡眠期间电刺激的影响，并为睡眠期间突触可塑性如何改变神经活动提供更好的机制见解。这项工作还将有助于改进大脑启发技术。例如，深度学习可以通过实现睡眠的记忆功能而变得更加灵活，获得更好的分类能力。