The tendency to consume large amounts of nicotine can be alleviated by changing the level of the nicotinic receptor protein in the brain, US scientists report in the journal Nature.
Among people who smoke, there are people who become very addicted and smoke a lot. Paul Kenny and colleagues from the Scripps Research Institute studied the effect of a gene variant encoding a nicotinic receptor fragment on nicotine addiction in rodents.
Nicotine stimulates a fragment of the so-called alpha-5 subunit of the nicotinic acetylcholine receptor in the brain. There are a lot of these types of receptors in a special part of the brain responsible for inhibiting the feeling of pleasure, the so-called the award system.
The authors of the study showed that rodents lacking this receptor become addicted to large amounts of nicotine, unattractive to normal animals. They also observed that manipulating the levels of the nicotinic receptor in the reward system in the brain alters the amount of nicotine consumed by rodents. Thus, by increasing the receptor level, nicotine addiction can be alleviated.
Research explains why some variants of the gene encoding the alpha-5 nicotinic receptor make people more susceptible to cigarette addiction, and others provide a signal to inhibit the enjoyment of high doses of nicotine – which helps reduce smoking. (PAP)