Lack of coordination between neural assemblies of key brain regions causes memory loss: Study

Failure of neural assemblies to sync together at the right time leads to the memories being lost

Absence of coordination between multiple neural assemblies formed within and between the hippocampus and prefrontal cortex in the brain could lead to memory loss, according to a new study in mice.

The study has found that neural assemblies - multiple separate groups of neurons that join forces to process information - connected inside and across these key brain regions support learning, remembering and recalling memories.

Failure of these neural assemblies to sync together at the right time leads to the memories being lost, the study said.

The study led by researchers from the universities of Bristol (UK) and Heidelberg (Germany) is published in the journal Currently Biology.

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Short-term memory relies on two key brain regions: the hippocampus and the prefrontal cortex.

How do you keep track of what to do next? What happens in the brain when your mind goes blank?

The researchers set out to find answers to such questions by establishing how brain regions, namely the hippocampus and the prefrontal cortex, interacted with one another as memories are formed, maintained and recalled at the level of neural assemblies.

The study also wanted to understand why sometimes memory fails.

"Neural assemblies" were first proposed over 70 years ago, but have proved difficult to pinpoint.

Using brain recordings in rats, the research team has shown in the study that memory encoding, storage and recall is supported by dynamic interactions incorporating multiple neural assemblies formed within and between the hippocampus and prefrontal cortex.

When the coordination of these assemblies fails, the animals made mistakes, the study found.

"Our results make potential therapeutic interventions for memory restoration more challenging to target in space and time.

"On the other hand, our findings have identified critical processes that determine a success or failure in remembering. These present viable targets for therapeutic interventions on the level of neural assembly interactions," said Michał Kucewicz, lead author of the study.

"Our findings add to the evidence that the neural substrates of memory are more distributed in anatomical space and dynamic across time than previously thought based on the neuropsychological models," said Matt Jones, senior author of the paper and professor at Bristol.

The research team presumes the same neural mechanisms would work in human patients to restore memory functions impaired in a particular brain disorder.