Pubdate: Thu, 22 Feb 2007
Source: Star, The (South Africa)
Copyright: Independent Newspapers 2007
Contact:  http://www.thestar.co.za/
Details: http://www.mapinc.org/media/423
Author: Reuters

'LIKE PUFFING ON COCAINE'

Washington - Smoking causes long-lasting changes in the brain similar 
to changes seen in animals when they are given cocaine, heroin and 
other addictive drugs.

A study of the brain tissue of smokers and nonsmokers who had died 
showed that smokers had the changes, even if they had quit years 
before, the team at the National Institute on Drug Abuse reported.

"The data show that there are long-lasting chemical changes," said 
Michael Kuhar of Emory University in Atlanta.

"The chemical changes alone suggest a physiological basis for 
nicotine addiction."

A team led by Bruce Hope of the National Institutes of Health, 
analysed levels of two enzymes found inside brain cells known as neurons.

These enzymes help the neurons use chemical signals such as those 
made by the message-carrying compound dopamine.

Smokers and former smokers had high levels of these enzymes, the 
researchers reported in the Journal of Neuroscience.

Hope said other studies had seen the same thing in animals given 
cocaine and heroin - and it was clear that the drugs were causing the effects.

"This strongly suggests that the similar changes observed in smokers 
and former smokers contributed to their addiction," he said.

Experts on smoking have long said that nicotine is at least as 
addictive as heroin.
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MAP posted-by: Beth Wehrman