Shrooms limit brain blood flow and connections


(photo by Curecat/Wikimedia Commons)

Turn off your mind, relax, and float downstream, indeed. A new scientific study suggests that psilocybin -- the psychedelic drug found in magic mushrooms -- doesn't "turn on" parts of your brain but rather restricts blood flow and connections between the regions of the brain tied to perception and cognition. Imperial College London psychopharmacology researcher Robin Carhart-Harris presented the results of this study, in which 30 volunteers were injected with psilocybin and underwent brain scans, at last week's Breaking Convention conference on psychedelic consciousness. Interestingly, the data helps support psilocybin's potential use to treat depression. From New Scientist:
Less blood flow was seen in the brain regions known as the thalamus, the posterior cingulate and the medial prefrontal cortex. "Seeing a decrease was surprising. We thought profound experience equalled more activity, but this formula is clearly too simplistic," says Carhart-Harris. "We didn't see an increase in any regions," he says.

Decreases in connectivity were also observed, such as between the hippocampus and the posterior cingulate and medial prefrontal cortex.

"Under psilocybin you see a relative decrease in 'talk' between the hippocampus and these cortical hub regions," says Carhart-Harris. "Changes in function in the posterior cingulate in particular are associated with changes in consciousness."

Psilocybin has a similar chemical structure to serotonin – a hormone involved in regulating mood – and therefore binds to serotonin receptors on nerve cells in the brain. The drug may have therapeutic potential because the serotonin system in nerves is also a target for existing antidepressants.

"Psychedelic drug cuts brain blood flow and connections" (Thanks, Jody Radzik!)