Could “forgetting” be the cure to addictions
30 November 2015
The research groups of Dr Benjamin Boutrel, PD, MER1 from the Psychiatry Department, Faculty of Biology and Medicine, CHUV and Prof. Pierre Magistretti from the University of Lausanne and the EPFL published an article in the prestigious journal Molecular Psychiatry on the 27th October 2015. The study carried out at the Centre for Psychiatric Neurosciences of the CHUV, shows that it is possible to erase even deep-rooted memories linked to drug consumption providing the possibility to help former drug addicts from falling again into overwhelming drug memory-induced relapse.
It seems that substance addiction is tightly linked to long-term memory formation processes induced by the drug experience and one of the key issues in the fight against addiction is prevention of relapse, precipitated by drug memories that associate a context with the positive drug-taking experience.
Understanding the mechanisms of long-term memorisation for drug cues
For over three years Dr Benjamin Boutrel’s research group has been collaborating with Prof. Pierre Magistretti towards an understanding of the cellular and molecular mechanisms responsible for the persisting memories associated with a positive experience of cocaine use. This type of learning relies on high levels of energy consumption and the results, published in Molecular Psychiatry 27 October, show that liberation of the metabolite lactate from astrocytes, (the cells that surround and feed the neurons in the brain), plays a critical role in the acquisition, retrieval and long-term maintenance of positive memories associated with drug taking.
Blocking formation of a long-term memory
This is the first demonstration that by blocking a metabolite transfer pathway between neurons and astrocytes it is possible to permanently erase a memory that associates the positive effect of cocaine and the context in which the drug is taken.
Dr. Boutrel reveals the promising aspects of this result “Our results demonstrate that it is possible to erase persistent memories which could potentially help the suffering former drug addicts to continue their fight to overcome drug dependence. The discovery points to a promising therapeutic target that could reduce the impact of drugs on long-term mental health”.
The crux of the results is the role of lactate in a distinct area of the brain involved in positive and negative memory formation as well as in establishing conditioned learning behaviours such as addictive behaviour. But beyond conditioned responses to drugs lie intention, decision-making and personal choices that can be extinguished by excessive drug taking.
The next goal of the research will be to see if these results, observed in rats conditioned to passive cocaine exposure, are also true for higher animals who are free to choose if they consume or not.
This study was carried out within the framework of the NCCR-Synapsy.
B Boury-Jamot, A Carrard , J L Martin, O Halfon, P J Magistretti, B Boutrel;
Disrupting astrocyte-neuron lactate transfer persistently reduces conditioned responses to cocaine.
Molecular Psychiatry 21:1070-1076, Oct 2015. doi:10.1038/mp.2015.157 >
Author : Melanie Hirt, EPFL