Scientists Reverse Depression In Mice By Reactivating Happy Memories

tonegawa laboratory

Earlier this year, French neuroscientists achieved a remarkable feat. Hacking into the brains of mice, they switched the emotional character of their memories, turning a neutral recollection into a positive one.

Now, neuroscientists at the Massachusetts Institute of Technology’s Tonegawa Lab have taken another major step forward in the science of memory manipulation. In a study published this week in Nature, the researchers succeeded in reversing depression-like behavior in mice by artificially reactivating happy memories.

The findings could have some exciting implications down the road for the treatment of depression in humans. If scientists are able to manipulate the brain cells where memories are housed, we may one day be able to develop pharmaceutical therapies for depression that are more targeted than antidepressants, which work across the entire brain.

“For treatment, we’d first have to isolate a particular memory and then artificially activate it at will,” Steve Ramirez, a graduate student at the university and the study’s lead author, told The Huffington Post in an email. “As of now, we can only really do that in animals and for humans we’re using our data simply as a basic science framework for how these circuits operate and how we can tinker with them.”

Hotwiring the memory.

How did they do it? First, the researchers exposed the mice to positive social experiences, which allowed them to isolate the brain cells that held the happy memory of the experience. Then, they tricked those brain cells into responding to pulses of light. Some time after the social interactions passed, researchers were able to reactive the positive memories by shooting a beam of light into the brain cells where they were stored.

Then, the researchers induced depression-like symptoms — such as giving up easily on a challenging task and losing pleasure —> Read More