French researchers have shown that activation of nicotine receptors in mice increases their sensitivity to stress. A mechanism that could end up in humans.
A cigarette break and worries go away… The image is shared by many and is one of the reasons why some people start smoking. A study carried out on mice, however, contradicts the idea that cigarettes relax.
Researchers at the Neurosciences Paris-Seine laboratory (CNRS/Inserm/UPMC) and the Institute of Molecular and Cellular Pharmacology (CNRS/Université de Nice Sophia Antipolis) have attempted to evaluate the impact of social stress in mice by activating or blocking nicotine receptors in animals. The result: Signs of social stress are amplified when mice are exposed to nicotine and suppressed when receptors are deactivated.
If we add nicotine, it only takes one day, instead of ten, and we get the same effects in terms of social stress in mice,”explains Philippe Faure, research director at the CNRS. This suggests that nicotine can potentiate the effects of stress.” A social stress which, in this rodent, usually occurs after ten days when confronted with aggressive congeners. It is characterized by avoidance of similarities and less attraction to sugars.
“All this allows us to show that the stress pathways are not independent of the nicotine receptor,”explains Professor Faure. Applied to humans, it would mean that smoking increases the effects of stress. According to the researcher, it is ” not obvious ” that the mechanisms described with the mouse are identical in humans. If nicotine were to act in the same way in our brain, it could explain our reactions in situations of stress linked to social relations, especially at work. For this social stress is not manifested within the human species by the direct aggression of our fellow human beings, nor by the establishment of a hierarchy with dominant figures, but rather by a negative view of our place in society.
The problem of the feeling
The solution to feel good about yourself? Throw his cigarettes in the trash can, could we answer that? Problem, lack of nicotine also creates stress, and smoking gives the impression of relaxing, when it would be the opposite according to the study. The vicious circle will then become self-sustaining, since the lack of stopping makes it very difficult and nicotine increases the stress that smoking is supposed to relieve. For people who use tobacco to manage their anxieties, the stress generated by nicotine and the effects of withdrawal must be treated in parallel.
The study does not yet know whether only social stress, which is just one of many stressful pathways, is influenced by nicotine. They will work to understand, in mice always, how the nicotinic receptor acts on the dopamine system. Which is at the origin of many of the attitudes of animals and humans. As a source of tension in our relationships with others, smoking may also be the cause of other behavioral problems.