Quit smoking: Can’t put down your cigarettes? A miswired brain could be to blame
Last updated at 9:26 AM on 31st January 2011
Want to quit? Scientists have found a genetic fault that makes it far harder to give up smoking
Thousands of smokers who claim they simply cannot quit no matter how hard they try could blame their genes.
Scientists have learned a brain pathway that, if not functioning correctly, can lead to an uncontrollable desire to smoke.
The fault lies in a receptor protein that is normally activated by the nicotine in cigarettes and dampens the desire for yet more of the drug.
The team found that when rats were genetically changed to block the protein they consumed far more nicotine than control animals.
Professor Paul Kenny, of the Scripps Research Institute, Florida, said: ‘These findings point to a promising target for the development of potential anti-smoking therapies.’
The study, published online in Nature, specifically focused on the chemical alpha-5 in a brain pathway known as the habenulo-interpeduncular tract.
Co researcher Dr Christie Fowler said: “It was unexpected that the habenula, and brain structures into which it projects, play such a profound role in controlling the desire to consume nicotine.
‘The habenula appears to be activated by nicotine when consumption of the drug has reached an adverse level. but if the pathway isn’t functioning properly, you simply take more.’
She said the data could clarify why some people are far more vulnerable to the addictive properties of nicotine and more likely to develop smoking-associated diseases such as lung cancer.
The NHS estimates around one in five adults in the UK smokes as do six per cent of children aged 11 to 15. Half of all long-term smokers will die prematurely due to a smoking-related disease. In 2008, smoking caused 83,900 deaths in England.
Scientists have already established that a tendency towards smoking can be inherited.
Quit smoking: Can’t place down your cigarettes? A miswired brain could be to blame