The idea of targeting and erasing select memories has long been a prominent trope in sci-fi, seen in movies like 'Eternal Sunshine of the Spotless Mind' and 'Superman II,' and literature like Philip K. Dick's 'We Can Remember It for You Wholesale' (later adapted as the movie 'Total Recall') and John C. Wright's 'The Golden Age.' But scientists have also done serious research into targeted memory loss, looking for drugs and procedures to remove crippling memories in persons with post-traumatic stress disorder (PTSD) or drug addictions.
New research published in the journal 'Biological Psychiatry' takes a big step towards making it a reality, proving that associations can be selectively erased in rodents without disrupting other memories. Researchers trained mice and rats to self-administer methamphetamine by pressing a lever and then associate that behavior and a meth high with a room that was distinct from other environments.
They discovered these associations form differently than other memories, and they could disrupt them by injecting a drug into the brain that inhibits the function of a protein called actin. They effectively erased memory cues associated with the meth room, but other memories, such as those involved with food rewards, weren't affected. What's more, the memories were destroyed passively. In other words, patients undergoing such a treatment wouldn't need to actively retrieve each associative memory to have them erased.
The technique is not yet ready for human use, as scientists need to learn how to safely target actin in the brain without affecting it in other areas of the body. But in the future, researchers are optimistic that a technique like the one studied here could be used to help rid individuals with psychiatric disorders from harmful associations. For recovering addicts, for example, associative memories can be dangerous – various cues, including scents, flavors, or even a specific group of friends, can trigger overwhelming cravings that reel them back into the world of drug abuse. Such cues can also cause people suffering from PTSD to relive traumatic experiences.
"We see this as being a pharmaceutical therapy to go along with cognitive-behavioral therapy for people with substance abuse disorder or post-traumatic stress disorder," says study leader Courtney Miller of the University of North Carolina, Chapel Hill. "We could give them a fighting chance and show them a world not fraught with landmines."