Overview
- NIH researchers showed that semaglutide raises levels of the signaling molecule cyclic adenosine monophosphate, or cAMP, in GLP1R-expressing neurons of the area postrema, a hindbrain region that helps control appetite.
- The team found that cAMP responses vary across individual neurons on a continuum from brief spikes to sustained signals, a pattern the authors link to receptor internalization or degradation and to why patients show different responses and weight-loss plateaus.
- Pharmacologic blockade of the cAMP-degrading enzyme PDE4 with the drug roflumilast converted short cAMP spikes into prolonged responses in mouse tissue, pointing to a possible way to lengthen the drug’s cellular action.
- The study also used loss-of-function experiments to show that disrupting Gs or cAMP signaling in those neurons abolished semaglutide’s weight-loss effects, confirming that intact Gs–cAMP coupling is required for the drug’s action.
- Published in Nature Metabolism on May 22, 2026, the experiments relied on real-time fluorescence imaging of mouse brain tissue over hours, so longer-term animal studies and human trials are needed to test safety, durability, and clinical benefit.