Hallucinogen chemistry guides antidepressant drug discovery

Scientists have long sought the secrets of the 5-HT2A serotonin receptor-a central nervous system receptor that binds hallucinogenic compounds, including LSD and psilocybin. Many hope to discover why these molecules cause hallucinations when they bind to 5-HT2A while other compounds that bind to the receptor, including serotonin, do not. LSD and psilocybin have been shown to treat mood disorders such as depression, and scientists wonder if they can design molecules that maintain that mood-altering ability without causing hallucinations. Researchers now report a structural biology-guided strategy for making such molecules. A team led by Sheng Wang of the Chinese Academy of Sciences and Jianjun Cheng of ShanghaiTech University determined the crystal structures of the 5-HT2A receptor bound to LSD, psilocin (the active form of psilocybin), serotonin, or lisuride, a nonhallucinogenic treatment for Parkinson’s disease. After visualizing the differences in how those molecules bind, the researchers then designed