研究人员发现，睡眠过程中重新出现了与学习相关的神经活动模式，这种重复活动可能是巩固记忆的一个重要因素，新成果发表在日前在线出版的《自然—神经科学》期刊上。这是科学家们第一次在内侧前额叶皮质（mPFC）中观察到这种重复活动，而且这种活动类似于发生在大脑海马区域内的神经活动模式，海马区域与记忆的形成和恢复有关。

　　在老鼠学习如何从迷宫中找到出路，以及处于睡眠状态的后学习过程中，Sidney Wiener和同事记录了来自老鼠大脑内侧前额叶皮质中的几组神经元活动。当老鼠们在迷宫中学习如何找出路时，内侧前额叶皮质中神经元的活动发生了变化，而在它们睡觉时，类似的活动重复出现了。通常情况下，这些重复事件出现的时间与海马区域内的固化活动同步。

　　推荐原始出处：

　　Nature Neuroscience 12, 919 - 926 (2009)31 May 2009 | doi:10.1038/nn.2337

　　Replay of rule-learning related neural patterns in the prefrontal cortex during sleep

　　Adrien Peyrache1, Mehdi Khamassi1,2, Karim Benchenane1, Sidney I Wiener1 & Francesco P Battaglia1,3

　　Slow-wave sleep (SWS) is important for memory consolidation. During sleep, neural patterns reflecting previously acquired information are replayed. One possible reason for this is that such replay exchanges information between hippocampus and neocortex, supporting consolidation. We recorded neuron ensembles in the rat medial prefrontal cortex (mPFC) to study memory trace reactivation during SWS following learning and execution of cross-modal strategy shifts. In general, reactivation of learning-related patterns occurred in distinct, highly synchronized transient bouts, mostly simultaneous with hippocampal sharp wave/ripple complexes (SPWRs), when hippocampal ensemble reactivation and cortico-hippocampal interaction is enhanced. During sleep following learning of a new rule, mPFC neural patterns that appeared during response selection replayed prominently, coincident with hippocampal SPWRs. This was learning dependent, as the patterns appeared only after rule acquisition. Therefore, learning, or the resulting reliable reward, influenced which patterns were most strongly encoded and successively reactivated in the hippocampal/prefrontal network.

　　1 Laboratoire de Physiologie de la Perception et de l'Action, Collège de France, Centre National de la Recherche Scientifique, Paris, France.

　　2 Institut des Systèmes Intelligents et de Robotique, Université Pierre et Marie Curie – Paris 6, Centre National de la Recherche Scientifique, Paris, France.

　　3 Center for Neuroscience, Swammerdam Institute for Life Sciences, Faculty of Science, Universiteit van Amsterdam, Amsterdam, The Netherlands.