Watch a scary movie and it might keep you awake at night – but the fear fades and you’re soon able to sleep normally again. This change in behaviour as new experiences take precedent over older ones is called memory extinction and a gene called Tet1 has been shown to play a critical role in the process. In an experiment, mice that were genetically engineered to lack Tet1 retained their fear of a cage that gave them a mild electric shock, long after the power supply was disconnected – whereas normal mice soon overcame their fear. The picture shows the distribution of proteins (stained yellow) associated with the Tet1 gene in a region of the mouse’s brain known as the hippocampus. Scientists think that enhancing the activity of TET1 in humans might be an effective treatment for psychiatric problems linked to memory, such as post-traumatic stress disorder.
Written by Mick Warwicker
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