Psychedelic drugs such as psilocybin are being examined for possible benefits in treating mood disorders and substance abuse, and clinical and imaging studies have suggested these drugs can reset patterns of brain network activity. Because many brain scans infer neural activity from blood flow and oxygen, a team investigated whether those vascular signals remain reliable after psychedelic dosing.
Researchers at Washington University in St. Louis tested a psychedelic that acts on serotonin, a chemical that also helps control the widening and narrowing of blood vessels. In mice given the drug, blood flow no longer changed in the usual way relative to neuronal activity, meaning the normal neurovascular coupling was disrupted. Giving a second medication that blocks a specific serotonin receptor removed the unusual blood-flow effects. The team then used psilocybin in further mouse experiments and reanalyzed human fMRI data from people given psilocybin; both showed comparable changes in blood-flow signals.
The research was led by Adam Q. Bauer, Jordan G. McCall and Joshua S. Siegel; the study appears in Nature Neuroscience. The findings have important implications for how scientists and clinicians interpret blood flow–based neuroimaging after psychedelic use, and researchers say it is important to better understand these neurovascular effects as psilocybin is studied for PTSD, treatment-resistant depression, substance abuse and stroke.
Difficult words
- psychedelic — drugs that alter perception and mood
- psilocybin — a naturally occurring psychedelic drug
- neurovascular coupling — link between neural activity and blood flow
- serotonin — brain chemical that influences mood and vessels
- receptor — protein on cells that responds to chemicals
- neuroimaging — brain scanning methods that measure activity
- disrupt — to stop normal function or patterndisrupted
- implication — possible future effects or consequencesimplications
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Discussion questions
- How might disrupted neurovascular coupling change the way clinicians use brain scans after psychedelic treatment?
- What steps could researchers take to better understand neurovascular effects of psilocybin before wider clinical use?
- What potential risks or benefits should be considered when studying psilocybin for conditions like PTSD or treatment-resistant depression?
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