In the brain of rodents, Marseille researchers have succeeded in detecting a predictive marker. In this area of the brain, a vulnerability to cocaine or other drugs is noticeable.
The addictive potential of the drug is a source of questions for many researchers. After all, it is legitimate to wonder how can one be addicted to an opioid as destructive as heroin while knowing the detrimental effect on one’s health? The same is true of cocaine … According to experts, 21% of those who try become heavily dependent on it at some point in their lives. Another addiction and last example to consider to understand the premise of this study, nicotine. In 2002, the World Health Organization (WHO) estimated that there were more than a billion smokers and that cigarettes would kill 8 million people each year from 2002 to 2030.
Drugs are a global scourge, says report United Nations report as of 2019, approximately 35 million people worldwide suffer from drug use disorders. Faced with this observation, a team of neurobiologists from the Institute of Neuroscience of La Timone, in Marseille, has just communicated a study in the scientific journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).
An experiment carried out on rodents
Unfortunately it is not possible to guarantee the welfare of the animal during this experiment, since the rats were exposed to cocaine. To warn them that the latter is dangerous, an electric shock was administered to their legs. The purpose of this operation is to make rodents understand that a danger is linked to taking the psychotropic drug, or the rats were going to be wary of it or not. Result: 25% continued despite the punishment inflicted with an electric shock. This proportion of neo-drug addiction in rats is similar to the addictive phenomenon in humans, the study authors explain.
An area of the brain vulnerable to drugs
Before inflicting electroshock on rodents, the researchers simultaneously analyzed the electrical activity of their brains at a very specific location: this is the sutbhalamic nucleus. It is the area known for its motor aspect, researchers specializing in Parkinson’s disease target precisely to design treatments. Marseille neurobiologists therefore compared the activity of this nucleus in the two groups of rodents: those who had stopped taking drugs and the 25% who had become addicted. This time, the objective was to assimilate how this electrical activity in the nucleus could in some people be linked to something compulsive. When the brain detects compulsive action, the sutbhalamic area displayed a particular electrical signature with low oscillation frequencies. The researchers found that rodents that were not compulsive became compulsive after this area was activated. And this, despite the electric shocks in the legs. This confirms that there are predictive markers in this area.
A nucleus receptive to other drugs such as heroin, tobacco or alcohol
An electrical signature of the sutbhalamic nucleus is also triggered with other drugs, say the researchers at Timone. Using this discovery, researchers will be able to look at how to access this area of the brain in humans without causing irreversible damage. But this is a great step forward in helping humans fight their addictions.
