Information flow across hippocampal circuits during memory reactivation

During rest and sleep, the hippocampus reactivates patterns of neural activity that represent awake experiences during brief bursts of highly synchronized activity. This process is thought to play a critical role in memory consolidation by transferring the reactivated patterns to downstream brain regions. However, it remains unclear how the hippocampus ensures that these patterns are effectively transmitted while retaining the structure of the original experiences they represent. In this presentation, I will argue that hippocampal circuits are organized to efficiently and reliably output patterns of reactivated activity through a motif we term “anatomical convergence”. We revealed the presence of this motif using anatomical tracing of individual subiculum neurons and their presynaptic partners in CA1, combined with in vivo optical recordings in mice performing a spatial navigation task.