Study discovers memory switchboard that protects past knowledge

The brain may reuse some cells to store many different memories without mixing them up with or erasing older memories, a new study in mice suggests.

Led by NYU Langone Health researchers, the study revealed that about one in four memory cells in a brain area called the hippocampus acts as a shared "hub" that links incoming and outgoing signals.

Scientists have long wondered how the brain can be flexible enough to learn new information while also being stable enough not to forget past knowledge.

To shed light on this mystery, the investigators focused on a chain of connected areas linking the hippocampus, which sits deep inside the brain and helps organize new experiences into memories, and the neocortex, the brain's outer layer, which stores long-term information. These included the cornus ammonis 3 (CA3), a hippocampal region that sends in fast-changing information; cornus ammonis 1 (CA1), a hippocampal region that acts as a central hub; and the retrosplenial cortex, which plays a key role in navigation and scene reconstruction.