Scientists erase fear memories in the minds of mice using light

A team of scientists working out of the University of California has successfully managed to delete a memory of fear from the minds of mice, potentially opening up another avenue for treatment in fear conditions like PTSD and neurotic phobias.

Fear is one of the essential tools for any living organism to survive. The instinct to avoid dark woods and deep water is a deep rooted fear that keeps us safe from bears and sharks.

But there are times when fear goes beyond our necessity for survival, and becomes debilitating. The ability to delete negative memories could prove life changing for people who have experienced traumatic events and have their lives negatively affected by the repercussions.

According to its findings, the team has managed to achieve this feat by using a technique called optogenetics. Mice were injected with a virus that was able to affect the activation of specific neural pathways after being exposed to light.

Shocking results

The mice were given a fear response to sound by associating a small electric shock with a high pitched tone. To test that a fear response had been created, the mice were played the sound without the electric shock and still showed a negative reaction.

The mice were then injected with the virus that created light sensitive proteins in the section of the brain associated with that specific memory, and after the light stimulation, the mice completely lost their fear response.

This is not the first time that optogenetics has been used to try and manipulate fear. In a paper published in 2014, a team used a similar technique to reprogram a negative emotion to a positive one.

When The Guardian spoke to Peter Giese, a professor of mental health at King’s College London, he said that this technique is still a long way off being useable in treatment of people: “Exactly how this can be applied to humans is a little bit unclear to me.”

So while this is an interesting development, there is the possibility that we're still closer to curing PTSD with technology like VR.