People with Prader Willi syndrome, a genetic disorder, have an insatiable appetite. They never feel full, even after a hearty meal. The result can be life-threatening overeating and obesity.
According to a new study, their constant hunger results in part to disordered signaling in the brain’s cerebellum, a region of the brain also responsible for motor control and learning. An international research team spanning 12 institutions, led by J. Nicholas Betley, an assistant professor of biology in Penn’s School of Arts & Sciences, and Albert I. Chen, an associate professor at the Scintillion Institute, in San Diego, used clues from Prader Willi patients to guide investigations in mice that uncovered a subset of cerebellar neurons that signals satiation after eating.
When the researchers activated these neurons, the magnitude of the effect "was enormous," accordingly to Betley. The animals ate just as often as typical mice, but each of their meals was 50-75% smaller.
[...] "It's amazing that you can still find areas of the brain that are important for basic survival behaviors that we had never before implicated," Betley says. "And these brain regions are important in robust ways."
Aloysius Y. T. Low, Nitsan Goldstein, Jessica R. Gaunt, et al. Reverse-translational identification of a cerebellar satiation network, Nature (DOI: 10.1038/s41586-021-04143-5)