Memories initially formed in hippocampus gradually stabilize to cortex over weeks-to-months for long-term storage. The mechanistic details of this brain re-organization remain poorly understood. We recorded bulk neural activity in circuits that link hippocampus and cortex as mice performed a memory-guided virtual-reality task over weeks. We identified a prominent and sustained neural correlate of memory in anterior thalamus, whose inhibition substantially disrupted memory consolidation. More strikingly, gain amplification enhanced consolidation of otherwise unconsolidated memories. To gain mechanistic insights, we developed a technology for simultaneous cellular-resolution imaging of hippocampus, thalamus, and cortex throughout consolidation. We found that whereas hippocampus equally encodes multiple memories, the anteromedial thalamus preferentially encodes salient memories, and gradually increases correlations with cortex to facilitate tuning and synchronization of cortical ensembles. We thus identify a thalamo-cortical circuit that gates memory consolidation and propose a mechanism suitable for the selection and stabilization of hippocampal memories into longer-term cortical storage.

最初在海马体中形成的记忆在数周至数月内逐渐稳定在皮质中以进行长期存储。这种大脑重组的机制细节仍然知之甚少。当小鼠在数周内执行记忆引导的虚拟现实任务时，我们记录了连接海马体和皮层的回路中的大量神经活动。我们在前丘脑中发现了一个显着且持续的记忆神经相关性，其抑制大大破坏了记忆巩固。更引人注目的是，增益放大增强了原本未巩固的记忆的巩固。为了获得机制见解，我们开发了一种在整个巩固过程中对海马体、丘脑和皮质进行同步细胞分辨率成像的技术。我们发现，海马体同等地编码多种记忆，而前内侧丘脑优先编码显着记忆，并逐渐增加与皮层的相关性，以促进皮层整体的调整和同步。因此，我们确定了控制记忆巩固的丘脑皮质回路，并提出了一种适合将海马记忆选择和稳定到长期皮质存储中的机制。