Three distinct groups of neurons in the hippocampus are responsible for creating and storing memory copies:

• Early-born neurons form a long-lasting copy that strengthens over time, initially too weak to access but becoming stronger with age12

• Late-born neurons create a strong initial copy that fades over time, eventually becoming inaccessible12

• Intermediate neurons produce a more stable copy that remains consistent12

This tripartite system allows for a dynamic interplay between memory persistence and adaptability, with each neuronal group contributing uniquely to the overall memory process12.

This unique memory storage system serves several crucial functions. It ensures memory persistence while allowing for flexibility, enabling the brain to adapt memories to changing circumstances1. The interplay between different neuronal groups facilitates appropriate behavioral responses to new situations, balancing the need to retain past experiences with the ability to update and modify them2. This dynamic nature of memory storage demonstrates the brain's remarkable plasticity and capacity for adaptation, allowing individuals to learn from the past while remaining responsive to present conditions12.

The activation and timing of different memory copies significantly influence how we remember, modify, and utilize our experiences. Surprisingly, which copy is accessed can affect memory malleability - memories stored by late-born neurons shortly after acquisition can be modified and rewritten, while those retrieved from early-born neurons after a long time are more resistant to change1. This dynamic process underpins the brain's enormous memory capacity and plasticity. The interplay between these neuronal groups allows for a delicate balance between maintaining past knowledge and adapting to new information, enabling appropriate behavioral responses in changing environments1.

Understanding the brain's tripartite memory storage system could revolutionize treatments for memory disorders like Alzheimer's disease. Researchers hope that insights into memory encoding and modification processes might lead to therapies that soften intrusive memories or potentially recover those thought to be lost1. This newfound knowledge of memory dynamics opens avenues for developing targeted interventions that could enhance memory persistence or facilitate the updating of maladaptive memories, potentially improving outcomes for patients with various cognitive impairments2.