Dynamic regulation of Z-DNA in the mouse prefrontal cortex by the RNA-editing enzyme Adar1 is required for fear extinction

Spiralling fear linked to spiralling DNA

30 September 2020

The shape of DNA in the brain affects how well mice can ‘unlearn’ previously acquired fear memories, a finding that could lead to new treatments for post-traumatic stress disorder and other psychiatric conditions.

A team led by scientists at the University of Queensland showed that, during fear learning, anti-clockwise helices of DNA form in the mouse prefrontal cortex — the short-term memory centre of the brain.

During fear extinguishing, when mice were exposed to safe stimuli in similar environments, an enzyme known as ADAR1 latched onto the reverse-twisted DNA and converted the helix shape back to its normal, clockwise spiral.

Without ADAR1, the DNA got stuck in its backwards configuration and mice were unable to form non-fearful memories. The results thus provide a link between DNA flexibility and cognitive flexibility.

Supported content

References

1. Nature Neuroscience 23, 718–729 (2020). doi: 10.1038/s41593-020-0627-5