Targeting brain region may help smokers quit

Scientists have found that targeting a specific brain region may help smokers kick the butt. Researchers at the University of Massachusetts Medical School (UMMS) have identified the region of the brain responsible for symptoms of nicotine withdrawal, such as headache and anxiety, that keep smokers from quitting. They found that physical nicotine withdrawal symptoms are triggered by activation of GABAergic neurons (neurons that secrete GABA, the brain's predominant inhibitory neurotransmitter), in the interpeduncular nucleus. Interpeduncular nucleus is an area deep in the midbrain that has recently been shown to be involved in nicotine intake. "We were surprised to find that one population of neurons within a single brain region could actually control physical nicotine withdrawal behaviours," said Andrew R Tapper from the Brudnick Neuropsychiatric Research Institute at UMMS. "Most of the work in the field has been focused on the immediate effects of nicotine, the addictive component in tobacco smoke, on reward circuits in the brain," Tapper said. "But much less is known regarding what happens when you take nicotine away from someone who has been smoking for a long time that causes all these terrible withdrawal symptoms. "Our main goal was to understand what brain regions are activated or deactivated to cause nicotine withdrawal symptoms," Tapper added. Researchers conducted a series of experiments in mouse models and found that nicotine withdrawal symptoms can be activated or deactivated independent of nicotine addiction. "When we activated the GABAergic neurons in the interpeduncular nucleus, mice suffered withdrawal symptoms even if they had no previous nicotine exposure," Tapper noted. "There are very few treatments to help people quit smoking," Tapper said. "If you can dampen the activity of this brain region chemically during nicotine withdrawal then you would hopefully be able to help someone quit smoking because you could reduce some of the withdrawal symptoms that they are experiencing," he said. The study was published in the journal Current Biology.