Nicotine Impairs Brain's Ability to Tell When Stomach is Full

Source:  APA Monitor

Ex-smokers may gain weight after kicking the habit because nicotine permanently impairs the brain's ability to signal when the stomach is full, says a study at Yale University. The researchers found that in addition to attaching itself to addiction-causing neuronal sites such as dopamine receptors, nicotine also attaches itself to a receptor on neurons in the hypothalamus, which helps regulate appetite. Mouse studies show that this receptor comes to rely on nicotine for normal functioning, so when nicotine is no longer present, the hypothalamus is left with a reduced ability to regulate appetite properly. Some antismoking drugs, like the drug cytisine, which isn't sold in the U.S., contain nicotine-like compounds that target this receptor, which might prevent post-cessation weight gain, researchers say. (Science, June 10, 2011)