Hungry? It’s all in your head. Regulating appetite is a popular area of research within neuroscience. With the growing obesity epidemic, researchers are always looking to learn more about how our brain controls appetite. Appetite is different from hunger. Hunger results when the blood sugar drops and the stomach is empty. Appetite is when you want food, or a certain food, regardless of when you last ate. A new study conducted by a team of researchers from Baylor College of Medicine, Texas Children’s Hospital and the University of Texas Health Science Center has uncovered new information on how the brain controls appetite and how nicotine addiction could be related.
In the brain it’s known that the hypothalamus has a lot to do with appetite as well as other functions such as temperature regulation, control of food and water intake, sexual behavior and reproduction and emotional responses. This is what most researchers have focused on when studying appetite. There’s something else involved however. At the cellular level in the brain, there are certain neurotransmitters and receptors that are an important part of the process.
Senior study author Dr. Benjamin Arenkiel, an associate professor of molecular and human genetics and of neuroscience at Baylor wanted to study the effects of acetylcholine, which plays a part in brain activity. He states, “How the brain controls appetite has been mostly focused on the hypothalamus.
In addition, acetylcholine , a modulator of brain activity, has been proposed to play a role in appetite control, but this role had not been explored until now.”
Arenkiel and his team looked at the basal forebrain which has cells that produce the neurotransmitter acetylcholine. The research was conducted on lab mice. To determine whether acetylcholine helps control the appetite in the animals, the researchers modified the mice genetically so that the cells in the forebrain which produced acetylcholine were eliminated. The mice without these cells had huge appetites, wanting food almost constantly. Other mice in the study were altered so that the production of acetylcholine in the brain was increased. These mice had almost no desire for food. Dr. Arenkiel wrote, “They won’t starve themselves; but they will be almost anorexic. We think acetylcholine-producing cells in the basal forebrain are regulating the satiety cues in the brain.”
So how is this all related to nicotine? In the brain, nicotine binds to the same receptors on cells that control appetite and are impacted by acetylcholine. That’s why smokers are sometimes fearful of gaining weight if they quit. Nicotine is known to reduce the appetite, and many tobacco users don’t want to give up that effect. The study authors believe that this connection might be useful in developing drugs to treat obesity. Currently, medications to help people quit smoking act on the brain in much the same way as acetylcholine. The video below features Dr. Arenkiel talking about the research and what can be learned from the study, check it out.
Sources:
Baylor College of Medicine,
Wall Street Journal,
Nature
