Department of Electrical Engineering, Columbia University, New York, NY 10027.
Institute for Genomic Medicine, Columbia University Medical Center, New York, NY 10032.
Proc Natl Acad Sci U S A. 2023 Feb 14;120(7):e2207909120. doi: 10.1073/pnas.2207909120. Epub 2023 Feb 7.
Reactivation of long-term memories enables experience-dependent strengthening, weakening, or updating of memory traces. Although coupling of hippocampal and cortical activity patterns facilitates initial memory consolidation, whether and how these patterns are involved in postreactivation memory processes are not known. Here, we monitored the hippocampal-cortical network as rats repetitively learned and retrieved spatial and nonspatial memories. We show that interactions between hippocampal sharp wave-ripples (SPW-R), cortical spindles (SPI), and cortical ripples (CXR) are jointly modulated in the absence of memory demand but independently recruited depending on the stage of memory and task type. Reconsolidation of memory after retrieval is associated with an increased and extended window of coupling between hippocampal SPW-Rs and CXRs compared to the initial consolidation. Hippocampal SPW-R and cortical spindle interactions are preferentially engaged during memory consolidation. These findings suggest that specific, time-limited patterns of oscillatory coupling can support the distinct memory processes required to flexibly manage long-term memories in a dynamic environment.
长期记忆的再激活使经验依赖性的记忆痕迹增强、减弱或更新成为可能。尽管海马体和皮质活动模式的耦合有助于初始记忆巩固，但这些模式是否以及如何参与再激活后的记忆过程尚不清楚。在这里，我们监测了老鼠在重复学习和检索空间和非空间记忆时的海马体-皮质网络。我们发现，在没有记忆需求的情况下，海马体尖波涟漪（SPW-R）、皮质纺锤波（SPI）和皮质涟漪（CXR）之间的相互作用被共同调节，但根据记忆和任务类型的阶段，它们被独立地招募。与初始巩固相比，在检索后的记忆再巩固过程中，海马体 SPW-R 和 CXR 之间的耦合窗口增加并延长。在记忆巩固过程中，海马体 SPW-R 和皮质纺锤波的相互作用被优先利用。这些发现表明，特定的、限时的振荡耦合模式可以支持灵活管理动态环境中长期记忆所需的不同记忆过程。
