@article{oai:oist.repo.nii.ac.jp:00001180,
 author = {Ghandour, Khaled and Ohkawa, Noriaki and Fung, Chi Chung Alan and Asai, Hirotaka and Saitoh, Yoshito and Takekawa, Takashi and Okubo-Suzuki, Reiko and Soya, Shingo and Nishizono, Hirofumi and Matsuo, Mina and Osanai, Makoto and Sato, Masaaki and Ohkura, Masamichi and Nakai, Junichi and Hayashi, Yasunori and Sakurai, Takeshi and Kitamura, Takashi and Fukai, Tomoki and Inokuchi, Kaoru},
 issue = {1},
 journal = {Nature Communications},
 month = {Jun},
 note = {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.},
 title = {Orchestrated ensemble activities constitute a hippocampal memory engram},
 volume = {10},
 year = {2019}
}