TY - JOUR
T1 - Orchestrated ensemble activities constitute a hippocampal memory engram
AU - Ghandour, Khaled
AU - Ohkawa, Noriaki
AU - Fung, Chi Chung Alan
AU - Asai, Hirotaka
AU - Saitoh, Yoshito
AU - Takekawa, Takashi
AU - Okubo-Suzuki, Reiko
AU - Soya, Shingo
AU - Nishizono, Hirofumi
AU - Matsuo, Mina
AU - Osanai, Makoto
AU - Sato, Masaaki
AU - Ohkura, Masamichi
AU - Nakai, Junichi
AU - Hayashi, Yasunori
AU - Sakurai, Takeshi
AU - Kitamura, Takashi
AU - Fukai, Tomoki
AU - Inokuchi, Kaoru
N1 - Publisher Copyright:
© 2019, The Author(s).
PY - 2019/12/1
Y1 - 2019/12/1
N2 - 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.
AB - 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.
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U2 - 10.1038/s41467-019-10683-2
DO - 10.1038/s41467-019-10683-2
M3 - Article
C2 - 31201332
AN - SCOPUS:85067305090
SN - 2041-1723
VL - 10
JO - Nature communications
JF - Nature communications
IS - 1
M1 - 2637
ER -