What if scientists could erase memories of battle in a soldier with post-traumatic stress disorder or help drug addicts forget their craving triggers?
A research team successfully erased drug-related memories in mice, without harming other recollections, a Scripps Research Institute press release reported.
"Our memories make us who we are, but some of these memories can make life very difficult," lead researcher Courtney Miller, a TSRI assistant professor, said. "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."
A vital reaction in the memory-making process is the "alteration of the structure of nerve cells via changes in the dendritic spines." The spines are "small bulb-like structures that receive electrochemical signals from other neurons. "
These changes naturally require a cell protein called actin to occur.The scientists blocked the creation of actin by blocking one of the rodents' molecular motors called "myosin II" during the maintenance phase of memories related to methamphetamine.
The animals immediately lost their drug-related memories. None of their other memories were damaged.
Mice and rats were conditioned to associate certain scents, sights, and feelings with methamphetamine. After their memories were "erased" the rodents showed no interest in the drug-related stimuli. Their response to stimuli that reminded them of food or other rewards was not affected, and the rodents still responded to the cues.
This finding could be extremely beneficial in a case where a drug addict associates an external stimuli (such as a park bench, cigarette, etc.) with getting a fix.
"We are focused on understanding what makes these memories different. The hope is that our strategies may be applicable to other harmful memories, such as those that perpetuate smoking or PTSD," Miller said.
