These people never feel full, but the problem lies in their cerebellum.

Prad-Willie syndrome (Prader-Willi syndrome) is a rare genetic disease in which people never feel full. This lack of satiety can lead to severe obesity, which in turn leads to life-threatening diseases. Although the fist-sized cerebellum has never been linked to hunger before, scientists have found that the cerebellum plays a key role in regulating satiety in patients with Prad-Willie syndrome.

It has long been thought that the cerebellum is mainly related to motor coordination, but this study suggests a new view that the cerebellum also plays a wide range of cognitive, emotional and behavioral roles. "We have opened up a whole new field of research on how the cerebellum controls food intake," said Albert Chen, a neuroscientist at the Seydron Institute (Scintillon Institute) in California.

In fact, the research project began with an inadvertent observation. Chen and the team found that when they activated some neurons outside the anterior part of the deep cerebellar nucleus (anterior deep cerebellar nuclei,aDCN), the mice stopped eating.

This aroused their interest and then contacted their collaborators at Harvard Medical School. Scientists at Harvard University recruited 14 patients with Prad-Willie syndrome and 14 non-sick people as experimental and control groups, and used functional magnetic resonance imaging (fMRI) to monitor their brain activity when they saw pictures of food under different feelings of satiety (just after eating or fasting for more than four hours).For many years, neuroscientists have focused on the hypothalamus (hypothalamus) or nucleus accumbens (nucleus accumbens), where the hypothalamus is the area of the brain involved in regulating energy balance, and the nucleus accumbens is the core of the brain's reward system. Elanor Hinton, a neuroscientist at the University of Bristow in the UK who was not involved in the study,

The results showed that the same brain region that Chen's team found in mice, compared with healthy people, showed significant abnormalities in neural activity in this brain region, the aDCN, in patients with Prad-Willi syndrome. For healthy people, aDCN after fasting for a period of time was activated after seeing food pictures compared with those just after eating, but for patients with Prad-Wiley syndrome, there was no significant difference in aDCN neural activity when seeing food photos in the two satiety states. This suggests that aDCN is helping us control our appetite and food intake.In order to further confirm this point, a number of research institutions have conducted more mouse experiments.

In order to further confirm this point, a number of research institutions have conducted more mouse experiments. The results showed that when aDCN neurons were activated, the activity of neurons which were happy to eat was inhibited, thus the food intake was significantly reduced. The findings are published in the journal Nature.This aroused their interest and then contacted their collaborators at Harvard Medical School.

For many years, neuroscientists have focused on the hypothalamus (hypothalamus) or nucleus accumbens (nucleus accumbens), where the hypothalamus is the area of the brain involved in regulating energy balance, and the nucleus accumbens is the core of the brain's reward system. Elanor Hinton, a neuroscientist at the University of Bristow in the UK who was not involved in the study, said the latest study found a new key area in the brain that regulates eating. Hinton continued: "I've been doing appetite-related research for the past 15 years or so, but I've never thought about the role of the cerebellum. I think this cerebellar study is very important not only for the treatment of Prad-Willie syndrome, but also for solving the problem of obesity in the general population. "

Now, researchers plan to test whether this neural circuit in the brain can be controlled by transcranial magnetic stimulation (Transcranial Magnetic Stimulation), a non-invasive intervention technique. Chen said that if the test is successful, they hope that the technology will eventually enter clinical trials.