Orexin in the brain decides between exercise or food

Researchers at the Swiss Federal Institute of Technology in Zurich(ETH) have discovered that the brain messenger orexin is essential for choosing between exercise and eating. According to a press release, the research findings could help people who find it difficult to motivate themselves to exercise.

According to the World Health Organization, 80 percent of adolescents and 27 percent of adults do not get enough exercise. In studies with mice, the team was able to show that the neurotransmitter orexin and the associated orexin neurons in the brain determine the decision between exercise and snacking. Compared to the well-studied so-called happiness hormone dopamine, the mode of action of orexin is still largely unexplored; the neurotransmitter was only discovered 25 years ago.

In their experiments, the ETH researchers compared normal mice with mice whose orexin system was blocked. According to the press release, the mice with an intact orexin system spent twice as much time on the running wheel and half as much time at a milkshake bar set up for them as the mice with a blocked orexin system. The researchers assume that orexin could also be responsible for this decision in humans.

"It will now be a matter of verifying our results in humans as well," said Daria Peleg-Raibstein, group leader at ETH and co-leader of the study, in the press release. "If we understand how the brain mediates between food intake and physical activity, we can develop more effective strategies to combat the global obesity epidemic and associated metabolic disorders." The results of the study were recently published in the journal "Nature Neuroscience". ce/eb