| First Author | Ghandour K | Year | 2019 |
| Journal | Nat Commun | Volume | 10 |
| Issue | 1 | Pages | 2637 |
| PubMed ID | 31201332 | Mgi Jnum | J:282465 |
| Mgi Id | MGI:6323842 | Doi | 10.1038/s41467-019-10683-2 |
| Citation | Ghandour K, et al. (2019) Orchestrated ensemble activities constitute a hippocampal memory engram. Nat Commun 10(1):2637 |
| abstractText | 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 Ca(2+) 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. |
