Nicotine gateway drug: prepares brain for cocaine

Nicotine may strengthen an individual's response to cocaine.

The Los Angeles Times:

Nicotine appears to be a potent "gateway" drug that enhances the effects of cocaine and possibly boosts the chances of becoming addicted, researchers reported Wednesday in a landmark paper on drug addiction.

While the study was performed in lowly mice, the findings suggest that reducing smoking and the use of other tobacco products -- and even nicotine replacement products and exposure to secondhand smoke -- in humans may have the bilateral impact of curbing addiction to other addictive substances.

"If our findings in mice apply to humans, a decrease in smoking rates in young people would be expected to lead to a decrease in cocaine addiction," the authors wrote.

Researchers led by Dr. Amir Levine at Columbia University in New York treated mice with nicotine and then exposed them to cocaine. The mice whose brains had been exposed to nicotine responded differently to the cocaine (exhibiting more characteristics of addiction) compared to mice who weren't exposed first to nicotine. Reversing the order of the drugs by exposing mice to cocaine first then nicotine had no such effect on behavior.

Further, the study demonstrated that nicotine influences substances called histone proteins in the reward center of the brain that in turn activates certain genes and leads to an exaggerated response to cocaine.

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