Activating Happy Memories Can Reverse Depression In Mice, Scientists Say

With each passing study, scientists are coming closer to understanding the debilitating mental illness that currently affects millions of Americans — depression.

According to a study published in the journal Nature, neuroscientists now have a better insight into depression-like behavior in mice. The study was led by Susumu Tonegawa and his colleagues at the MIT (Massachusetts Institute of Technology) in Cambridge.

Scientists increased activity of neurons in the area of the brain that stores positive memories. By artificially manipulating the memory of mices and reactivating happy memories, depression-like behaviors were reversed, treating the depression, The Huffington Post reported.

Researchers used genetic engineering to create mice and memory cells from a brain area called the dentate gyrus (DG). The DG was subsequently hacked by reactivating the memory cells with a blue light-emitting optical fibre implanted in the denate gyrus.

Furthermore, male mice were exposed to a positive experience — creating memories for testing. The male mice were also exposed to stressors that caused depression-like symptoms. While the mice were in a state of depression, researchers used light to stimulate the DG and reactivate the memory cells for the positive experience, therefore reversing the depressive-like symptoms.

“More recently, the researchers used variations of the engram method to create false memories in mice, trigger lost memories and even retrain engram cells to encode a positive memory instead of a negative one.”

But, as Nature writes, these new findings will give scientists more confidence when it comes time to find new treatment for depression in humans. Finding out how to counteract depression is one of the biggest challenges for neuroscientists. The exact cause of depression is still far from being fully understood, scientists say.

However, as the Inquisitr reported a few months ago, scientists were able to implant happy memories in mice using a technique called memory manipulation. The study was initiated by French scientists at the Centre National de la Recherche Scientifique (CRNS). The primary goal was to grab some insight on memory manipulation that would later help researchers find new treatment for PTSD (Post Traumatic Stress Disorder) in humans.

PTSD is an anxiety disorder that occurs after someone has experienced or witnessed a traumatic event. This mental disorder is particularly popular among military veterans and survivors of natural disasters. It too can cause depression and chronic stress overtime. But PTSD is a whole other ball game — something researchers are also striving to fully understand in the near future.

[Photo via Koichi Kamoshida / Getty Images]