期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2018
卷号:115
期号:2
页码:E310-E316
DOI:10.1073/pnas.1714082115
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:The memory for a new episode is formed immediately upon experience and can last up to a lifetime. It has been shown that the hippocampal network plays a fundamental role in the rapid acquisition of a memory of a one-time experience, in which the novelty component of the experience promotes the prompt formation of the memory. However, it remains unclear which neural circuits convey the novelty signal to the hippocampus for the single-trial learning. Here, we show that during encoding neuromodulatory input from locus coeruleus (LC) to CA3, but not CA1 or to the dentate gyrus, is necessary to facilitate novel contextual learning. Silencing LC activity during exposure to a novel context reduced subsequent reactivation of the engram cell ensembles in CA3 neurons and in downstream CA1 upon reexposure to the same context. Calcium imaging of the cells reactivated in both novel and familiar contexts revealed that suppression of LC inputs at the time of encoding resulted in more variable place fields in CA3 neurons. These results suggest that neuromodulatory input from LC to CA3 is crucial for the formation of a persistent memory in the hippocampus.