Is there a common path to the psychedelic experience? Nitro oxide, ketamine and LSD share fMRI network changes in human cortex

Nitrous oxide, ketamine, and LSD show overlapping neurobiological effects on brain network connectivity during altered states. A Michigan Medicine team used fMRI to measure brain activity in healthy participants given nitrous oxide and compared those patterns to fMRI data from separate studies using ketamine and LSD. They also included a propofol group to help distinguish changes specific to psychedelic-like effects rather than general anesthesia. Across the drugs, researchers observed decreased connectivity within a particular network but increased connectivity across multiple networks. The drugs also shared increased connectivity between specific brain regions located in a proposed cortical "hot zone" for shaping conscious experience. The overlap in activity patterns suggests common underlying biology that could inform how psychedelics might be used therapeutically.