Treatments for pain or addiction targeting the κ-opioid receptor often cause hallucinogenic side effects. To understand this, cryo-electron microscopy mapped the receptor's structure with various G-proteins and compounds. These detailed maps uncovered molecular controls for G-protein binding and drug selectivity, showing distinct preferences. This clarifies opioid action, establishing a foundation for developing safer, pathway-selective therapies.
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.