Scientists Can Make Your Memory ‘Young’ Again—By Reprogramming Your Brain

Getty Images3 min readHere’s what you’ll learn when you read this story:In a recent study, researchers reprogrammed neurons to a more youthful state. Through a series of tests, the team concluded that the mice remembered “lost” memories.This treatment method could prove useful in treating neurodegenerative diseases such as Alzheimer’s, but there is much more development to be done before the therapy hits clinics.Brain fog can be scary. It might appear innocently, like losing your car keys or forgetting what date you scheduled that appointment on. Some of this memory loss is normal—it’s just a natural side effect of your brain healthily aging. However, neurodegenerative conditions can cause a more severe form of memory loss called dementia, where patients progressively lose their ability to communicate, problem-solve, and think clearly. But now, experts believe memory loss and symptoms from conditions like Alzheimer’s disease may be reversible.Researchers from the École Polytechnique Fédérale de Lausanne (EPFL) Institute in Switzerland managed to partially “reprogram” neurons and restore memory function in mice with a special gene therapy cocktail. Their results were published this past March in the peer-reviewed journal Neuron. The team did not respond to requests for comment.In the study, the scientists focused on three genes: Oct4, Sox2, and Klf4 (referred to together as OSK). Previous studies have shown that OSK-targeting therapies can reverse other age-related diseases such as glaucoma, a condition that causes vision loss. The EPFL researchers engineered a virus “switch” that could activate quick and controlled pulses of OSK. Instead of treating the entire brain, the team specifically targeted engram cells, or the groups of neurons that store specific memories.Engrams themselves are not a new discovery. Evolutionary biologist and zoologist Richard Semon is credited with introducing the concept more than a century ago, and the notion that memory is stored in a localized region of the brain goes back even farther. This idea opens up an exciting possibility: If we can identify where memories are located, could we reactivate lost ones? The research has progressed in recent years, thanks to technological advancements, and the recent study is a result of that. But the real question is whether the gene therapy was successful—and it was.After treatment, the mice’s memories were essentially shunted back into a younger state. The researchers found that reprogrammed engrams displayed molecular behavior of more youthful cells. Using a variety of tests, including a water maze, the team determined that the OSK therapy restored memory in multiple areas of the brain.For instance, after treatment, memory performance in the dentate gyrus of the hippocampus—a region of the brain associated with learning and short-term memory—returned to levels similar to younger control groups. The team also found that the treatment helped recover memories formed weeks prior, meaning the treatment was effective in the engrams of the medial prefrontal cortex, or the part of the brain associated with long-term memory.So does this mean that the groundbreaking treatment could eventually reboot already-forgotten memories in human patients?“Yes, in a sense,” Nik Papageorgiou, a member of the communications team at EPFL, writes in a press statement. “The memory itself isn’t deleted; instead, the ‘hardware’ (the neurons) holding that memory is refurbished. By making the neurons young and flexible again, the brain can once again access and process those memories as if it were decades younger.”What makes the team’s method especially promising for clinical application is its precision. The therapy specifically targets and reprograms the cells that are crucial for learning, which also happen to be the areas that are failing because of neurodegenerative disease. This approach avoids attempting to reprogram the whole brain, which is dangerous. Likewise, the therapy affects such a small area, and the gene activation is so quick, that it avoids interfering with necessary cellular function.While the recent study in mice may seem far off from a life-changing Alzheimer’s treatment for humans, Papageorgiou explains that the findings still represent a “major shift in thinking.”“It suggests that cognitive decline isn’t just about losing neurons—it’s about neurons becoming ‘too old’ to function,” he writes. “If we can rejuvenate them, we might be able to restore function even after the disease has started.”Download Pop Mech Digital IssuesPopular MechanicsPopular MechanicsPopular MechanicsPopular MechanicsEmma Frederickson graduated from Pace University where she studied communication and media. Prior to her time as an editor, she was a freelance science reporter. She enjoys covering everything from shipwrecks to pimple popping, but her favorite topics include climate change, conspiracy theories, and weird biology. When she’s not writing, Emma can be found hopping between coffee shops on the hunt for the world’s best oat milk cappuccino.