PDF(Pubmed)
Abstract：
Neuronal ensembles are crucial for episodic memory and spatial mapping. Sleep, particularly non-REM (NREM), is vital for memory consolidation, as it triggers plasticity mechanisms through brain oscillations that reactivate neuronal ensembles. Here, we assessed their role in consolidating hippocampal spatial representations during sleep. We recorded hippocampus activity in rats performing a spatial object-place recognition (OPR) memory task, during encoding and retrieval periods, separated by intervening sleep. Successful OPR retrieval correlated with NREM duration, during which cortical oscillations decreased in power and density as well as neuronal spiking, suggesting global downregulation of network excitability. However, neurons encoding specific spatial locations (i.e., place cells) or objects during OPR showed stronger synchrony with brain oscillations compared to non-encoding neurons, and the stability of spatial representations decreased proportionally with NREM duration. Our findings suggest that NREM sleep may promote flexible remapping in hippocampal ensembles, potentially aiding memory consolidation and adaptation to novel spatial contexts.
摘要：
神经元合奏对于情景记忆和空间映射至关重要。Sleep,特别是非快速眼动(NREM)，对记忆巩固至关重要，因为它通过大脑振荡触发可塑性机制，从而重新激活神经元集合。这里,我们评估了它们在睡眠期间巩固海马空间表征中的作用.我们记录了执行空间对象位置识别（OPR）记忆任务的大鼠的海马活动，在编码和检索期间，通过干预睡眠分开。成功的OPR检索与NREM持续时间相关，在此期间，皮质振荡的功率和密度以及神经元尖峰下降，表明网络兴奋性的全球下调。然而,编码特定空间位置的神经元(即，与非编码神经元相比，OPR期间的位置细胞）或对象与大脑振荡表现出更强的同步性，空间表示的稳定性与NREM持续时间成比例下降。我们的研究结果表明，NREM睡眠可能会促进海马集合的灵活重定位，可能有助于记忆巩固和适应新的空间环境。
