For some, it’s love at first puff. For others, it’s just plain sickening. Why do smokers have such different reactions to their first cigarette—and why are some so much more tempted to try a second?
It’s all about the pleasure, the reward… and the neurotransmitter dopamine, according to researchers at the University of Western Ontario. The scientists have identified a specific pathway in the brains of rats that uses dopamine to relay signals associated with nicotine’s rewarding properties. The chemical pathway, called the “mesolimbic” dopamine system, is also involved with the addictive effects of alcohol and cocaine. The naturally occurring differences in dopamine receptors, says team leader Steven Laviolette, may explain why some people are more vulnerable to nicotine addiction.
