DNA repair gene critical for memory consolidation

21 December 2018

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Queensland Brain Institute neuroscientists have found that the brain’s process for repairing DNA is also important for consolidating memories and allowing rapid brain adaptation.

The discovery, by Associate Professor Timothy Bredy, Dr Wei Wei and Dr Xiang Li, challenges current thinking on the significance of DNA repair to the brain’s ability to adapt to changes.

“The protein Gadd45γ plays a critical role in repairing DNA,” A/Prof Bredy said. “We discovered that Gadd45γ is also a key player in regulating how the human body memorises being frightened.

Dr Wei said, “By demonstrating a DNA repair factor like Gadd45γ acts as a transcriptional regulator during memory formation, we’ve added to the growing understanding that DNA breakage and repair is an important process for brain adaptation.

“It is yet another example of the many ways molecular processes are delicately and precisely controlled to facilitate learning.”

The molecular process behind memory consolidation

In order for our memories to be stored, gene expression and protein synthesis occurs in neurons that are activated depending on the experience. 

This activation changes the strength of connections between neurons so certain information is retained.

“Few people have previously considered that DNA repair factors such as Gadd45γ might also be involved in memory, but this research shows they are necessary and important,” Dr Wei said.

The research furthers the contention that DNA is not a static entity and has the potential to allow the brain to rapidly adapt to environmental changes.

Gene activity peaks twice after a fearful experience 

Gadd45γ was found to activate genes critical for fear memory twice within a matter of hours after a fear-inducing incident.

This consolidates on earlier studies that discovered such genes peak twice during learning experiences.

“They are activated immediately when there is an incident, then temporarily become quiet, only to peak again several hours later during the consolidation of the memory,” Dr Wei said.

The study was published in the Journal of Neuroscience and supported by organisations including Australia’s National Health and Medical Research Council and the National Institutes of Health in the United States.

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