Professor Flavio Donato’s research group at the Biozentrum, University of Basel, uses mouse models to investigate how memories are stored in the brain and how they change throughout life. His team has now revealed that in the hippocampus, a brain region responsible for learning from experience, a single event is stored in parallel memory copies among at least three different groups of neurons, which emerge at different stages during embryonic development. The early-born neurons are responsible for the long-term persistence of a memory, with their memory copy becoming stronger over time. In contrast, the memory copy of the same event created by the late-born neurons is very strong initially but fades over time. Neurons emerging in between the two extremes during development produce a more stable memory copy.
The memories stored for a short time after acquisition by the late-born neurons can be modified and rewritten. This means that remembering a situation shortly after it has happened primes the late-born neurons to integrate present information within the original memory. On the other hand, remembering the same event after a long time activates the early-born neurons to retrieve their copy, making it more difficult to modify the associated memory. The brain’s plasticity allows for the dynamic storage of memories, highlighting its enormous memory capacity. Understanding how memories are stored and modified in the brain could potentially help soften intrusive memories or bring back those believed to be lost forever.
The activation of specific memory copies and their timing could have significant consequences on how we remember, change, and use our memories. The brain faces the challenge of balancing the need to remember past events to make sense of the world while also adapting to changes and making appropriate choices for the future. The researchers hope that by understanding what drives memories to be encoded and modified in the brain, they can improve memory-related issues that impact daily life. Memory persistence through dynamics is a delicate act to balance, and researchers now have an entry point to further understand and study this intricate process.
Overall, the ability to turn experiences into memories provides a foundation for learning and adapting to new situations. The brain’s memory model must be dynamic and adaptable to help predict the future and choose the best course of action. The discovery of multiple memory copies in the hippocampus sheds light on how memories are stored and can change over time. Understanding the dynamics of memory storage can lead to potential interventions to address problematic memories and enhance memory retrieval. The complexity of memory storage in the brain showcases its remarkable plasticity and capacity for adaptation.
