Smoking: Inserm manages to suppress nicotine addiction thanks to the light

Another step against smoking. A new study by Inserm has shown that it is possible to manipulate nicotine addiction in mice quickly and reversibly.

"This innovative technology provides a better understanding of the role of different nicotine receptors and neuronal pathways in setting up, maintaining nicotine addiction, as well as in the processes of withdrawal and relapse, important for the identification of new therapeutic targets for nicotine addiction," says Alexandre Mourot. , Research Manager.

Violet light helps stop the attraction for nicotine

Nicotine, the main addictive agent of tobacco, works on the brain by binding to nicotine receptors. Based on this assumption, scientists have modified the nicotine receptor in mice to react a chemical nano switch to light. Under the influence of the violet light, the switch folds the nicotine to remedy: the receiver is "off". Under the influence of the green light, or in the dark, the switch is unfolded and the nicotine works: the receiver is "on".

In concrete terms, violet light helps stop the attraction for nicotine. The team compared the time that mice spent in two compartments, with or without nicotine. Under green light, when nicotine could exert its effect, they noticed that animals preferred the compartment with nicotine. However, under violet light, the mice spent so much time in each compartment, which proved that they were no longer attracted by nicotine.

A special nicotine receptor

For this study, the researchers concentrated on a particular nicotine receptor, type b2, and an important area of ​​the reward circuit that delivers dopamine. In an intravenous injection of nicotine, dopamine neurons react by increasing their electrical activity. The resulting release of dopamine is the key to setting up addiction.

Nicotine is a naturally occurring chemical compound in tobacco plants, which is one of the alkaloids. Its properties for the plant are the removal of parasites (fungicide, acaricide, insecticide). In people, nicotine causes tobacco addiction and feelings of relaxation, pleasure, reduced anxiety and depression.

In smoking, there is an initial "peak" where the concentration of nicotine in the body continuously increases until the total burning of the cigarette is between 5 and 7 minutes. Then this concentration decreases rapidly: after one hour it decreases by half; after two hours, more than a quarter of the initial peak remains in the blood.

The damage among the younger generations

There will still be some traces of nicotine in the body. After 4 days the blood has removed all the nicotine it contained. The other nicotine and tobacco derivatives responsible for cravings (cotinine, anabasin and nornicotins) can be eliminated much longer in certain organs of the body, such as kidney or adipose tissue. It takes on average three weeks to be completely virgin traces of nicotine, the evacuation of the product is mainly via the urine.

The damage to the younger generations can be considerable. According to a recent study, the arteries of smokers who smoke at the age of 17 start to stiffen. Arterial stiffness indicates that the blood vessels begin to be damaged, making the bed of future cardiovascular problems. We are talking about heart attacks or strokes.

"In France more than 13 million people smoke," the government said in March, recalling that tobacco is a "major source of cancer, cardiovascular disease and respiratory failure, responsible for 73,000 deaths per year". Worldwide, 11 million cigarettes are sold daily, accounting for 39 billion profits, the equivalent of Luxembourg GDP.

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