Consume a lot of alcohol causes memory loss and cravings

UNITED STATES.

One of the many challenges to tackling alcohol and other substance use-related disorders is the risk of relapse even after progressing towards recovery. Even annoying fruit flies thirst for alcohol, and because the molecular signals involved in the formation of reward memories and the avoidance of memories are very similar to those of humans, they constitute a good model for the study.

New research on flies reveals that alcohol diverts this way of forming memories and modifies the proteins expressed in neurons, creating cravings. A few drinks a night change the way memories are formed at the fundamental molecular level, as stated in an article about the published work this Thursday in the magazine & # 39; Neuron & # 39 ;.

The lead author of the article, Karla Kaun, assistant professor in neuroscience at Brown University, USA, worked with a team of university students, technicians and postdoctoral researchers. discover the molecular signaling pathways and gene expression changes involved in creation and maintaining reward memories.

One of the things I want to understand is why drugs can produce really rewarding memories when they're actually neurotoxins, "says Kaun, an affiliate of the Brown & Brain Research Institute. Carney. All drugs of abuse (alcohol, opiates, cocaine, methamphetamine) have undesirable side effects. They cause nausea or hangover in people, why do we find them so rewarding? Why do we remember good things that concern them and not bad ones? My team is trying to understand at the molecular level what drugs do to memories and why they crave smoking. "

Once researchers understand what molecules change when cravings are formed, can find out how to help alcoholics and addicts recover by decreasing the length of memories of cravings or its intensity, according to Kaun.

Fruit flies have only 100,000 neurons, while humans have more than 100 billion. The small scale, as well as the fact that generations of scientists have developed genetic tools to manipulate the activity of these neurons in the circuit and at the molecular level, have turned the fruit fly into an ideal model organism for the first time. 39; team. Kaun will separate the genes and molecular signaling pathways involved in alcohol reward recipes, says this expert.

Under the direction of Emily Petruccelli, a postdoctoral researcher, now an assistant professor and with her own laboratory at the University of Southern Illinois in the United States, the team used genetic tools to turn off Selectively key genes while learning to find alcohol. This allowed them to see what proteins were needed for this rewarding behavior.

ACTIVATION AND DEACTIVATION OF GENES

One of the proteins responsible for the preference of flies for alcohol is Notch, the researchers found. Notch is the first "domino" of a signaling pathway involved in the development of embryo, brain development and brain function in adults in humans and all over the world. other animals. The molecular signaling pathways do not differ from a cascade of dominoes: when the first one falls (in this case, the biological molecule is activated), it pulls more, it activates more and so on.

One of the dominoes descending into the alcohol-affected signaling pathway is a gene called the dopamine-2 receptor, which produces a protein in neurons that recognizes dopamine, the neurotransmitter of "feeling good". "It is known that the receptor similar to dopamine-2 is involved in coding the pleasant or aversive memory of a memory," says Petruccelli. And alcohol takes this path of preserved memory to form cravings.

In the case of the alcohol reward pathway studied, the signaling cascade neither activated nor deactivated the dopamine receptor gene, nor increased or decreased the amount of protein produced, Kaun said. Instead, it had a more subtle effect: it changed the version of the protein produced by a "letter" of a single amino acid in an important area.

We do not know what are the biological consequences of this small change, but one of the important conclusions of this study is that scientists must not only determine which genes are turned on or off, but which forms of each gene are activated or not. . Kaun– emphasizes. We believe that these results may be translated into other forms of addiction, but no one has investigated this. "

With information from Europa Press

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