New Haven, Conn.- A new study by Yale researchers shows that priornicotine exposure in mice can increase their motivation to workfor food, weeks after their last exposure to nicotine, a finding thatruns counter to the popular belief that nicotine exposure curbsappetite.
The study, to be published in an upcoming issue ofPsychopharmacology, also sheds new light on the role played by certainnicotinic acetylcholine receptors when it comes to the reinforcingaspects of nicotine.
The study provides insight into one of the most vexing issues relatingto smoking cessation, one that discourages many people from attemptingto quit smoking, the prospect of weight gain. "Although acute nicotinecan act as an appetite suppressant, these data are the first to suggestthat repeated exposure to nicotine has the opposite effect, thatnicotine increases motivation for food for weeks following exposure tothe drug," said Darlene Brunzell, associate research scientist in theDepartment of Psychiatry and first author of the study.
"This research suggests that when young people take up smoking toregulate their weight, this may be counterproductive in addition tobeing harmful to their health," said Stephanie O'Malley, professor ofpsychiatry and principal investigator for the Center for Nicotine &Tobacco Use Research at Yale. "More research is needed to determine howexactly that works, but this does show that there could be a connectionbetween exposure to nicotine and subsequent weight gain in someindividuals."
In addition, the study identifies which nicotinic receptors areinvolved in nicotine's control over cues. "We knew previously that cuesplay a critical role in nicotine and tobacco consumption in animals andhumans," said Brunzell. "These studies show that Beta 2 nicotinicreceptors are necessary for nicotine's ability to increase the controlthat cues have over behavior." said Dr. Darlene Brunzell, Ph.D., firstauthor of the study. he also said, in addition, that the findings runcounter to the popular belief that acute nicotine exposure curbsappetite. "These data are the first to suggest that repeated exposureto nicotine has the opposite effect, that nicotine increases motivationfor food for weeks following exposure to the drug."
O'Malley said that the research has significance when it comes todeveloping solutions for smokers who gain weight after they quitsmoking. She noted that weight concerns keep many people, particularlywomen, from attempting to quit. Any information about the mechanism forweight gain could help the researchers at Yale and elsewhere figure outhow to address that concern. In the meantime, she said, the researchmight help discourage people from starting to smoke to regulate theirweight.
For more information about CENTURY/TTURC, please see www.quitwithyale.org
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