How old memories fade away…

By Casey Frye, CCNN Writer

family album
MIT researchers hope to treat PTSD with the gene responsible for memory extinction. Someday, you might just have to rely on old school photo albums to jog your memory!

Imagine if a bully jumped out of the neighbor’s bushes to scare you… every single day. After a while, just walking by those shrubs might give you the chills! Heck, even if you’re on the other side of town, passing by green hedges might get you sweaty, triggering bad memories. However, if the neighbor one day moved away, it wouldn’t be quite so scary anymore. The bad memories will eventually fade away and be replaced with new ones. This phenomenon is known as “memory extinction,” and now, a group of researchers from MIT know what gene is responsible for causing it.

It’s called the Tet1 gene, and it appears to have a lot of control over memory extinction. In order to prove this, the MIT researchers used two groups of mice: one with an active Tet1 and the other with an inactive gene. From there, the scientists taught the rodents how to be afraid of a cage by shocking them, you know, similar to a bully jumping out of the bushes. Eventually, all the mice became afraid of going into the cage.

However, if the rodents had the gene, they eventually forgot their fears and formed new memories once the shocking stopped. But, if the creature didn’t have Tet1, they never left their fear behind. It’s as if possessing the gene aids memory extinction. “If there is a way to significantly boost the expression of these genes, then extinction learning is going to be much more active,” says Li-Huei Tsai, a professor of neuroscience at MIT and the senior author of the paper.

The researchers hope this study will help individuals who are suffering from post-traumatic stress disorder (PTSD), a condition where scary experiences that happened in the past haunt people in the present. The idea is that maybe if researchers can find a way to enhance the Tet1 gene in their brains, the PTSD sufferer will experience memory extinction and focus more on newer memories.

Featured image courtesy of Christine Daniloff from MIT. Image of family courtesy of P & K’s Mommy on Flickr.