London, June 11. Obesity might have a neurobiological side to it. A new study suggests that its origin may be in the brain.
David Erritzoe and his colleagues at Copenhagen University Hospital, Denmark, studied the brains of 47 people of normal weight and 29 overweight people. They found that the brains of overweight people have more receptors for the neurotransmitter serotonin than those of normal weight, reported online edition of New Scientist.
Nurotransmitter serotonin, thought to be secreted by the Pineal Gland, is called a neurohormone because of its specific regulatory effect on the activity of the endocrine glands in the human body.
The brain operates by millions of nerve cells (neurons) communicating with each other by transmitting molecules. These molecules are known as neurotransmitters.
Serotonin is one of the many neurotransmitters believed to be responsible for various functions, including how we feel on a daily basis.
The scientists used positron emission tomography to map the brains of the participants and found the drugs that block the serotonin receptor 5-HT2A are associated with weight gain.
Erritzoe, who presented the work at a meeting of the Society of Nuclear Medicine in San Diego, California, found slightly higher concentrations of the receptor in overweight people.
Whether the difference in receptor number is a cause or an effect of being overweight remains uncertain, but twin studies suggest that genes are important in determining its prevalence.
"I think it's important for people with weight problems to know that there may be a neurobiological side to it," said Erritzoe.