Orchestrated ensemble activities constitute a hippocampal memory engram
Orchestrated ensemble activities constitute a hippocampal memory engram
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DOI：
10.1038/s41467-019-10683-2
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发表时间：
2019-06-14
影响因子：
16.6
通讯作者：
Inokuchi, Kaoru
中科院分区：
文献类型：
--
作者：
Ghandour, Khaled;Ohkawa, Noriaki;Inokuchi, Kaoru
大脑通过一组称为记忆印迹细胞的神经元来存储和回忆记忆。然而，目前还不清楚这些细胞是如何组成相应的记忆痕迹的。我们建立了一个独特的成像系统，结合Ca2+成像和记忆印迹识别提取记忆印迹活动的特点，通过可视化和区分记忆印迹和非记忆印迹细胞。在这里，我们发现，在海马中检测到的记忆印记细胞显示出更高的重复活动比非记忆印记细胞在新的上下文学习。记忆印迹细胞在学习过程中的总活动模式在学习后的记忆处理过程中是稳定的。在一个单一的记忆印迹群体中，我们检测到了几个由学习过程中集体激活的神经元组成的子集合。一些子集合在学习后睡眠中优先出现，并且这些重放的子集合更有可能在提取过程中被重新激活。这些结果表明，子集合代表不同的信息片段，然后编排构成整个记忆。
The brain stores and recalls memories through a set of neurons, termed engram cells. However, it is unclear how these cells are organized to constitute a corresponding memory trace. We established a unique imaging system that combines Ca2+ imaging and engram identification to extract the characteristics of engram activity by visualizing and discriminating between engram and non-engram cells. Here, we show that engram cells detected in the hippocampus display higher repetitive activity than non-engram cells during novel context learning. The total activity pattern of the engram cells during learning is stable across post-learning memory processing. Within a single engram population, we detected several sub-ensembles composed of neurons collectively activated during learning. Some sub-ensembles preferentially reappear during post-learning sleep, and these replayed sub-ensembles are more likely to be reactivated during retrieval. These results indicate that sub-ensembles represent distinct pieces of information, which are then orchestrated to constitute an entire memory.