Addiction Relapse Prevention Possible by ‘Erasing’ Drug-Associated Memories

Recovering drug addicts can be prevented from relapsing by selectively erasing drug-associated memories through a new process now being developed by scientists at the Florida campus of The Scripps Research Institute (TSRI), according to MedicalXpress.

The new research, now being undertaken by TSRA scientists, is built on a 2013 study by Associate Professor Courtney Miller, the team's leader, that was published in the journal Biological Psychiatry.

As Miller then said: "Our memories make us who we are, but some of these memories can make life very difficult. Not unlike in the movie Eternal Sunshine of the Spotless Mind, we're looking for strategies to selectively eliminate evidence of past experiences related to drug abuse or a traumatic event. Our study shows we can do just that in mice - wipe out deeply engrained drug-related memories without harming other memories."

The team found that drug-associated memories could be selectively erased by targeting "actin," the protein that provides the structural scaffold supporting memories in the brain. But actin is also critically important throughout the body so any attempt at generally and indiscriminately inhibiting actin, even once, could be fatal.

Eventually, Miller and her team found a way to target brain actin with better accuracy. They found a safe route to get to the brain actin using "blebbistatin," a compund that acts on "nonmuscle myosin II," a molecular motor that supports memory formation.

They found that a single injection of blebbistatin is enough to successfully disrupt long-term storage of drug-related memories, and consequently in blocking relapse for at least a month, at least in the animal models of methamphetamine addiction.

As Ashley M. Blouin, a member of Miller's team, told MedicalXpress, "Drugs targeting actin usually have to be delivered directly into the brain. But blebbistatin reaches the brain even when injected into the body's periphery and, importantly, the animals remained healthy.

"We now have a viable target and by blocking that target, we can disrupt, and potentially erase, drug memories, leaving other memories intact," said Miller.

"The hope is that, when combined with traditional rehabilitation and abstinence therapies, we can reduce or eliminate relapse for meth users after a single treatment by taking away the power of an individual's triggers," she added.

The new selective memory-erasing therapeutic pharmaceutical protocols now being developed at TSRI, once clinically tested, can potentially also be used for the treatment of other neuropsychiatric disorders aside from drug addiction, like post-traumatic stress and phobic anxiety disorders.