A research team at Washington University in St. Louis tested a psychedelic that acts on serotonin. Serotonin helps control the widening and narrowing of blood vessels, so the team wanted to see if blood-flow signals still match neural activity.
In mice given the drug, blood flow did not change in the usual way when neurons were active. A second medication that blocks a specific serotonin receptor removed those unusual blood-flow effects. The researchers then used psilocybin in more mouse experiments and reanalyzed human fMRI data; both showed comparable changes. The finding means blood flow–based scans may not always show true neural activity after psychedelics.
Difficult words
- psychedelic — a drug that changes perception and thinking
- serotonin — a chemical in the body that affects blood vessels
- receptor — a protein on cells that receives signals
- psilocybin — a psychedelic compound found in some mushrooms
- blood flow — movement of blood through body vesselsblood-flow
- neural — related to nerves or brain cells
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Discussion questions
- Why did the researchers test the drug in mice?
- How could changes in blood flow affect brain scans?
- Have you seen a brain scan before? How did it seem to you?
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