Psychologists have argued for decades that unwanted memories
associated with drug use can sometimes lead to relapse. It explore whether it is possible to erase such thoughts, scientists have shown it may be possible to selectively erase methamphetamine
-related memories in mice and rats through working on proteins found in the brain (essentially deactivating a neural pathway).
The basis of the new research was the way in which a 'memory' is formed. According to Science 2.0
, a memory is produced through the alteration of the structure of nerve cells via changes in the dendritic spines (bulb-like structures that receive electrochemical signals). These structural changes occur via actin, the protein that makes up the infrastructure of all cells.
For the study
, the research group 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’ brain with a chemical designed to breakdown the actin protein (an actin-depolymerizing agent). The scientists then tested the behavior of the mice 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 scientists behind the are not yet sure why powerful methamphetamine-related memories are also so fragile and it is unclear whether other types of memories can be 'erased'.
The research has been published
in the journal Biological Psychiatry
. The paper is titled "Selective, Retrieval-Independent Disruption of Methamphetamine-Associated Memory by Actin Depolymerization."