Scientists have found a way to erase very specific memories in mouse brains, helping drug-addicted lab rodents recover. 

Following up on a similar study they published in 2013, researchers from the Scripps Research Institute in Florida were able to selectively erase memories of methamphetamine in mice using a drug that disrupts a memory-related protein in the brain. 

In previous studies, the researchers found that memories of drug use are not stored in the same way as other memories. Actin, a protein that supports connections between neurons, normally stabilizes within a few minutes of a typical experience (like eating a really great dessert), but when it comes to drug memories like the thought of taking your first hit of meth, actin filaments keep changing in size, strengthening the connections between neurons even days after the original event. 

Neurobiologist Courtney Miller, one of the authors of the recent study in the journal Molecular Psychiatry, explains that a drug administered in the lab can be used to target only memories associated with addiction because of this unique instability. She writes in an email to mental_floss that “unlike the memory for food reward, the actin is cycling and, therefore, open to a breakdown of actin filaments (and consequently, spines) when the monomers are sequestered by Latrunculin [the treatment drug].” When the researchers targeted nonmuscle myosin IIB, a protein that drives actin polymerization (the process by which actin changes during memory storage), they were able to make lab mice forget memories associated with meth, but not erase other memories, such as those associated with a scary experience. 

Meth users might have developed associations with seemingly banal activities like handling money or chewing gum, meaning that reminders of their drug use (and the cravings that come along with them) are constantly lurking in everyday life. This technique removes the triggering memories that might induce drug cravings, helping prevent relapse, and could be a useful addition to rehabilitation therapy. 

However, the treatment is a long way from being ready for use by people. The researchers hope to start human trials in the next five years. And that’s if it even makes it to human trials—in cancer research, the success rate of a transfer from animal to human models is less than eight percent, and other fields face similar disappointments with treatments developed in animal models. 

[h/t: Washington Post]