Carriers of a genetic mutation show increased dependence on tobacco

Scientists at the Institut Pasteur, the French National Center for Scientific Research (CNRS) and Pierre and Marie Curie University (UPMC) have recently proven that, in mice, nicotine intake– nicotine is the main addictive substance in tobacco – is heavily regulated by a genetic mutation that is very common in humans. This mutation affects the neuronal nicotinic receptor, disrupting its function and resulting in partial inactivation of the "reward circuit". Carriers of this mutation therefore have to increase their consumption to feel the effects of tobacco. These results, published online on December 3, 2013 in Molecular Psychiatry, pave the way for the development of new smoking cessation treatments that target carriers of this mutation.

During , binds to , thus activating the "reward circuit", a neuronal system responsible for a number of responses – including a feeling of well-being – during normal function. The effect of nicotine on the brain compensates for withdrawal symptoms felt by smokers when they are deprived of tobacco. As a result, a person's tobacco consumption is closely linked to the sensitivity of these nicotinic receptors.

The teams led by Uwe Maskos, who heads the Integrative Neurobiology of Cholinergic Systems Unit at the Institut Pasteur / CNRS, and by CNRS scientist Philippe Faure, who manages the Neurobiology of Adaptive Processes laboratory (CNRS / UPMC), have recently made a discovery proving that nicotine addiction may be influenced by an individual's genetic heritage. These scientists show that, in mice, a genetic mutation resulted in a marked reduction in sensitivity to nicotine. Carriers of this gene therefore require a higher dose of tobacco than non-carriers in order to obtain the same amount of pleasure - somewhere on the order of three times more.

The mutation characterized by the scientists affects part of the nicotinic receptor. The presence of this mutation disrupts the normal function of the nicotinic receptor, partially inactivating the "reward circuit".

This mutation occurs frequently in humans. Other studies suggest that it is present in 35% of Europeans, and in nearly 90% of heavy smokers. These discoveries pave the way for the development of "personalized" smoking cessation treatments for individuals who carry this genetic mutation.

More information: Nicotine consumption is regulated by a human polymorphism in dopamine neurons, Molecular Psychiatry, December 3, 2013.

Related Stories

Internet addiction—Causes at the molecular level

date Aug 29, 2012

Everybody is talking about Internet addiction. Medically, this phenomenon has not yet been as clearly described as nicotine or alcohol dependency. But a study conducted by researchers from the University of Bonn and the Central ...

Recommended for you

Best friends may help poor kids succeed

date 7 hours ago

(HealthDay)—Children who grow up in poor neighborhoods face more obstacles in life, but new research suggests that having a best friend can help these kids succeed.

Emotion knowledge fosters attentiveness

date 10 hours ago

Young children, who possess a good understanding of their own emotions and of those of their fellow human beings early on, suffer fewer attention problems than their peers with a lower emotional understanding. Evidence of ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.