UR2NF-Neuropsychology and Functional Neuroimaging Research Unit Affiliated at CRCN - Centre for Research in Cognition and Neurosciences, Avenue F.D, Roosevelt 50, Bruxelles 1050, Belgium; UNI-ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Avenue F.D. Roosevelt 50, Bruxelles 1050, Belgium.
Biochem Pharmacol. 2021 Sep;191:114369. doi: 10.1016/j.bcp.2020.114369. Epub 2020 Dec 16.
Neuroplasticity refers to the fact that our brain can partially modify both structure and function to adequately respond to novel environmental stimulations. Neuroplasticity mechanisms are not only operating during the acquisition of novel information (i.e., online) but also during the offline periods that take place after the end of the actual learning episode. Structural brain changes as a consequence of learning have been consistently demonstrated on the long term using non-invasive neuroimaging methods, but short-term changes remained more elusive. Fortunately, the swift development of advanced MR methods over the last decade now allows tracking fine-grained cerebral changes on short timescales beyond gross volumetric modifications stretching over several days or weeks. Besides a mere effect of time, post-learning sleep mechanisms have been shown to play an important role in memory consolidation and promote long-lasting changes in neural networks. Sleep was shown to contribute to structural modifications over weeks of prolonged training, but studies evidencing more rapid post-training sleep structural effects linked to memory consolidation are still scarce in human. On the other hand, animal studies convincingly show how sleep might modulate synaptic microstructure. We aim here at reviewing the literature establishing a link between different types of training/learning and the resulting structural changes, with an emphasis on the role of post-training sleep and time in tuning these modifications. Open questions are raised such as the role of post-learning sleep in macrostructural changes, the links between different MR structural measurement-related modifications and the underlying microstructural brain processes, and bidirectional influences between structural and functional brain changes.
神经可塑性是指大脑可以部分改变结构和功能，以适应新的环境刺激。神经可塑性机制不仅在获取新信息（即在线）时起作用，而且在实际学习结束后的离线期间也起作用。使用非侵入性神经影像学方法已经在长期内一致证明了学习导致的大脑结构变化，但短期变化仍然更加难以捉摸。幸运的是，过去十年中先进的磁共振方法的迅速发展现在允许在短时间内跟踪精细的大脑变化，而不仅仅是跨越数天或数周的粗体积变化。除了时间的影响外，学习后睡眠机制已被证明在记忆巩固中起着重要作用，并促进神经网络的长期变化。睡眠被证明有助于在长时间的训练中进行结构修改，但在人类中，仍缺乏与记忆巩固相关的更快速的训练后睡眠结构效应的研究证据。另一方面，动物研究令人信服地表明睡眠如何调节突触的微观结构。我们旨在回顾文献，建立不同类型的训练/学习与由此产生的结构变化之间的联系，重点关注训练后睡眠和时间在调节这些变化中的作用。提出了一些悬而未决的问题，例如学习后睡眠在宏观结构变化中的作用、不同的磁共振结构测量相关变化之间的联系以及大脑微观结构过程、结构和功能脑变化之间的双向影响。
