December 6, 2012
Researchers Say Future PTSD Cure May ‘Block’ Recall Of Unwanted Memories
redOrbit Staff & Wire Reports - Your Universe Online
Researchers at Western University say that they have found a way to treat both Post-Traumatic Stress Disorder (PTSD) and drug addiction by selectively blocking the patient´s recall of memories.
Led by Nicole Lauzon, a PhD candidate in Professor Steven Laviolette´s lab at Western's Schulich School of Medicine & Dentistry, the researchers´ study has shed light on how a mechanism in the brain´s pre-limbic cortex regulates the recall of both negative experiences, like those associated with PTSD, as well as the positive memories that drug addicts associate with being high.
Even more significant, Lauzon´s team also believes that they have found a way to suppress the spontaneous recall of both traumatic and pleasurable memories without permanently changing the memories themselves.
The researchers published the results of their study online in the journal Neuropharmacology.
"These findings are very important in disorders like PTSD or drug addiction. One of the common problems associated with these disorders is the obtrusive recall of memories that are associated with the fearful, emotional experiences in PTSD patients. And people suffering with addiction are often exposed to environmental cues that remind them of the rewarding effects of the drug,” explained Laviolette, an associate professor in the Departments of Anatomy and Cell Biology, and Psychiatry.
“This can lead to drug relapse, one of the major problems with persistent addictions to drugs such as opiates. So what we've found is a common mechanism in the brain that can control recall of both aversive memories and memories associated with rewarding experience in the case of drug addiction."
Using lab rats, the researchers discovered that by stimulating a sub-type of dopamine receptor in the brain known as the "D1" receptor, they were able completely block the recall of both traumatic and reward-related memories.
"The precise mechanisms in the brain that control how these memories are recalled are poorly understood, and there are presently no effective treatments for patients suffering from obtrusive memories associated with either PTSD or addiction," explained Lauzon.
The researchers believe that if they can learn to block the recall of these memories in humans as well, then they may have a biochemical target for which to create new memory-blocking pharmaceuticals for the treatment of PTSD and drug addiction.
"In the movie, 'Eternal Sunshine of a Spotless Mind,' they attempted to permanently erase memories associated with emotional experiences," said Laviolette.
However, the team believes that their research could potentially lead to less invasive ways of curbing the recall of unwanted memories.
"The interesting thing about our findings is that we were able to prevent the spontaneous recall of these memories, but the memories were still intact. We weren't inducing any form of brain damage or actually affecting the integrity of the original memories."