Psychedelic substances like LSD and psilocybin show potential for treating neuropsychiatric disorders, primarily acting through the serotonin 5-HT2A receptor. However, 5-HT1A also contributes to the effects of tryptamine hallucinogens, especially 5-MeO-DMT from Colorado River toad toxin. Using cryo-EM structures, medicinal chemistry, and mouse behavior, researchers mapped how 5-MeO-DMT engages 5-HT1A. They characterized molecular determinants of signaling potency, efficacy, and selectivity at both 5-HT1A and 5-HT2A. A 5-HT1A-selective analogue of 5-MeO-DMT lacked hallucinogenic effects but retained anxiolytic-like and antidepressant-like activity in socially defeated animals, uncovering molecular aspects that may aid developing new neuropsychiatric medications.
Ariadne, a non-hallucinogenic analog of the hallucinogen DOM, demonstrates significant therapeutic potential in treating various conditions. In clinical trials, Ariadne led to rapid remission of psychotic symptoms in schizophrenia and improved cognition in elderly patients. It acts as a 5-HT<sub>2A</sub> receptor agonist with modest selectivity for 5-HT<sub>1</sub>, exhibiting lower signaling potency than DOM. Notably, in a Parkinson’s disease model, Ariadne alleviated severe motor deficits comparable to l-DOPA, positioning it as a promising candidate for future psychiatric and neurological therapies.