Biozentrum, Universität Basel, 4056 Basel, Switzerland.
Science. 2024 Aug 16;385(6710):eadk0997. doi: 10.1126/science.adk0997.
Memories are dynamic constructs whose properties change with time and experience. The biological mechanisms underpinning these dynamics remain elusive, particularly concerning how shifts in the composition of memory-encoding neuronal ensembles influence the evolution of a memory over time. By targeting developmentally distinct subpopulations of principal neurons, we discovered that memory encoding resulted in the concurrent establishment of multiple memory traces in the mouse hippocampus. Two of these traces were instantiated in subpopulations of early- and late-born neurons and followed distinct reactivation trajectories after encoding. The divergent recruitment of these subpopulations underpinned gradual reorganization of memory ensembles and modulated memory persistence and plasticity across multiple learning episodes. Thus, our findings reveal profound and intricate relationships between ensemble dynamics and the progression of memories over time.
记忆是动态的结构，其性质随着时间和经验的变化而变化。支持这些动态的生物学机制仍然难以捉摸，特别是关于记忆编码神经元集合组成的变化如何随时间影响记忆的演变。通过针对主神经元的发育不同的亚群进行靶向研究，我们发现记忆编码导致在小鼠海马体中同时建立多个记忆痕迹。这些痕迹中的两个是在早期和晚期出生的神经元的亚群中实例化的，并在编码后遵循不同的再激活轨迹。这些亚群的分歧招募为记忆集合的逐渐重组提供了基础，并调节了多个学习事件中的记忆持久性和可塑性。因此，我们的发现揭示了集合动态与记忆随时间的进展之间的深刻而复杂的关系。
