Researchers found that serotonin and psilocybin (the active compound in magic mushrooms) work through the same brain mechanism to suppress certain neural signals in a brain region called the claustrum. This region controls how different parts of the cortex communicate with each other. The study shows that psilocybin directly targets serotonin 5-HT1B receptors to quiet down signals from one brain area to another, which may explain how psychedelics change cortical network activity and alter consciousness.