Laboratory of Chemical Biology, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China; School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China.
3 papers in the library · 16 citations · publishing 2025-2026
The position of the hydroxyl group on the indole ring of psilocin analogs determines their ability to activate the 5-HT2A receptor and produce psychedelic-like effects. Analogs with the hydroxyl group at the 4th or 5th position (psilocin and bufotenine) show significantly higher agonistic activity and head-twitch responses than those with the group at the 6th or 7th position. Computer simulations reveal that the 4- and 5-position analogs form a crucial hydrogen bond with residue L229 and a stable salt bridge and hydrogen bond with residue D155, guiding them into the binding site. Analogs lacking these interactions fail to reach the orthosteric site and have poor receptor activity.
Psychedelics are being tested in over 200 clinical trials as potential treatments for psychiatric disorders, but how they work and their risks are not fully understood. The serotonin 2A receptor (5-HT2AR) is the main target of psychedelics. This study compared psychedelics with non-hallucinogenic analogues using cell and animal experiments, finding that 5-HT2AR signaling through a non-canonical Gi pathway is essential for hallucinogenic effects. Five cryo-electron microscopy structures of 5-HT2AR bound to these drugs were solved. A special contact between non-hallucinogenic analogues and the receptor biased signaling away from Gi. A derivative called DOI-NBOMe showed potent Gq-biased activity and therapeutic effects in mice without causing hallucinations. These findings reveal mechanisms of 5-HT2AR Gi signaling and guide the design of safer psychedelic-based drugs.
Psilocin, the active metabolite of psilocybin, induces psychedelic-like behavior in male mice by activating neurons in the medial prefrontal cortex (mPFC). Using c-Fos immunofluorescent labeling, the mPFC was the only brain region among several tested that was specifically associated with the head twitch response (HTR), a behavioral marker of psychedelic activity. A picomolar dose of psilocin directly into the mPFC triggered significant HTR. Optogenetic activation of these neurons increased spontaneous HTR, while acute inhibition suppressed drug-induced HTR. The findings establish the mPFC as a critical regulator of psilocin's psychedelic effects, offering insights for improving the clinical safety and therapeutic use of psychedelics.