Aiming to comprehend the dynamics of memory in brains, scientists conducted a new study on mouse models and examined how memories are stored and modified in the hippocampus.

The hippocampus is a tiny, complex structure of the brain that plays an important role in learning, memory, and emotions. 

Researchers from the University of Basel in Basel, Switzerland, found that memories of specific experiences are stored in the brain as multiple parallel copies distributed across a minimum of three different clusters of neurons.

These clusters emerge at different stages during embryonic development. The copies vary in terms of their duration, modifiability, and susceptibility to deletion over time.

Dynamics of memory preserves in the brain

Scientists sought to learn the dynamics of the brain, which preserves and adapts memories, to understand how these processes contribute to learning from past experiences and decision-making in changing environments.

The research team showed that the activation and timing of specific memory copies can significantly impact how we recall, modify, and utilize our memories.

Flavio Donato from the University of Basel explained in an official statement that the brain faces impressive challenges concerning memory. 

“On one hand, it must remember what happened in the past, to help us make sense of the world we live in. On the other, it needs to adapt to changes happening all around us, and so must our memories, to help us make appropriate choices for our future,” says Donato.

Understanding how past experiences impact decision-making could be vital because memories help living beings learn from the past and adapt to changing circumstances, thus influencing future decisions and behavior.

Scientists also note that until the discovery of multiple memory copies, the mechanism behind the brain regulating a memory’s dynamics remained a mystery.

Parallel copies of stored memories

Upon studying the hippocampus in mice, the team observed that parallel copies of stored memories in neuron clusters emerged at different phases during embryonic development. 

These copies vary in their accessibility over time, with early-born neurons maintaining long-term memories that become accessible only after some time, while late-born neurons store memories that are strong initially but fade over time. Middle-stage neurons store more stable memories.

“How dynamically memories are stored in the brain is proof of the brain’s plasticity, which underpins its enormous memory capacity,” stated first author Vilde Kveim.

This flexibility in memory storage explains how our brain can adapt memories over time, helping us learn from new experiences while still holding on to important long-term memories.

A statement by the researchers emphasizes that persistence through dynamics is a delicate act to balance, one for which they might now have an entry point to fully understand.

This finding could potentially help scientists treat issues such as traumatic memories that might be too overwhelming or intense for an individual to manage.

It could also aid in recovering memories that have faded or seem lost, offering new ways to manage and improve mental health.

Researchers are now aiming to understand the driving force behind how memories are encoded and modified in the brain, potentially leading to ways to alleviate the impact of intrusive memories.

The study was published in the journal Science.