Selective engram coreactivation in idling brain inspires implicit learning

• DOI: 10.1073/pnas.2201578119
• Publication Date: 2022-08-01T19:22:29Z
• Authors: Mohamed H. Aly; Kareem Abdou; Reiko Okubo-Suzuki; Masanori Nomoto; Kaoru Inokuchi
• Keywords: Engram; Sleep

Passive priming of prior knowledge to assimilate ongoing experiences underlies advanced cognitive processing. However, the necessary neural dynamics memory assimilation remains elusive. Uninstructed brain could also show boosted creativity, particularly after idling states, yet it unclear whether can spontaneously spark relevant assimilations. We established a paradigm that links/separates context-dependent memories according geometrical similarities. Mice exploring one four contexts 1 d before undergoing contextual fear conditioning in square context showed gradual transfer preexposed geometrically next day, but not 15 min. Anterior cingulate cortex neurons representing relevant, rather than distinct, were significantly coreactivated during postconditioning sleep only, their selective integration day testing. Disrupting coreactivations prevented while preserving recent consolidation. Thus, assimilating pertinent through coreactivation respective engrams represents underpinnings sleep-triggered implicit cortical learning.