Putting Bad Memories to Bed
Researchers selectively erase methamphetamine-related memories in mice and rats.
Unwanted memories associated with drug use can sometimes lead to relapse. But scientists have shown it may be possible to selectively erase methamphetamine-related memories in mice and rats through depolymerizing actin in the amygdala, according to a paper published yesterday (September 10) in Biological Psychiatry.
The scientists taught mice and rats to associate methamphetamine with various stimuli. Then, after the rodents consolidated their drug-related memories, the scientists infused some of the animals’ amygdalas with an actin-depolymerizing agent and then tested their behavior when exposed to drug-related stimuli. The control mice showed signs of methamphetamine-related memories, while mice with inhibited actin polymerization did not respond to the stimuli. The treatment mice did not experience global memory loss, however; they still responded to stimuli associated with food rewards or electric shocks.
The researchers chose to depolymerize actin because F-actin is known to be important for rapid changes in neural structures called dendritic spines, which are thought to be involved in memory maintenance.
“We are focused on understanding what makes [drug-related] memories different,” study coauthor Courtney Miller, a neurobiologist at The Scripps Research Institute in Jupiter, Florida, said in a press release. “The hope is that our strategies may be applicable to other harmful memories, such as those that perpetuate smoking or PTSD [post-traumatic stress disorder].”
