In an effort to explore the effect of psilocybin on the healthy brain, an international team of scientists created a biophysically realistic whole-brain model, described by the researchers as a “technical tour de force.” The researchers reported on this model in a paper published in the Proceedings of the National Academy of Sciences.
The groundbreaking model enabled them to observe how psilocybin impacts the activity of neurons and neurotransmitters. “Longer term, this could provide a better understanding of why psilocybin is showing considerable promise as a therapeutic intervention for neuropsychiatric disorders including depression, anxiety, and addiction,” they wrote in the paper.
Psilocybin and other psychedelics are known to affect the neurotransmitter balance of serotonin receptors in the brain, but up to this point “little has been known of this process,” write two of the paper’s authors, Morten L. Kringelbach and Gustavo Deco, in an email to Lucid News. The model they created sheds new light on these dynamics. “Using this model will be crucial for truly understanding how psilocybin can rebalance neuropsychiatric disorders such as treatment-resistant depression and addiction,” the researchers added.
To create the whole-brain model they analyzed functional resonance imaging (fMRI) data from 16 healthy subjects. Then, nine subjects each underwent two fMRI scans over separate sessions, in which they were given either a 2mg dose of psilocybin or a placebo saline solution. The findings reveal that when psilocybin was introduced, “neural networks were disrupted and neurotransmitters forged new pathways between neurons,” writes Mental Daily.
“It has long been a puzzle how the brain’s fixed anatomical connectome can give rise to so many radically different brain states; from normal wakefulness to deep sleep and altered psychedelics states,” write Kringlebach and Deco. The whole brain model they created is capable of addressing this puzzle, in addition to advancing scientific understanding of psilocybin.
The new model, they write, “will give us the much needed, causal tools for potentially designing new interventions to alleviate human suffering in neuropsychiatric disorders.”
They are currently using the model for a new psilocybin study for depression, conducted by Dr. Robin Carhart-Harris, who was also involved in this study.
Top image by Steve Jurvetson via Flickr. This graphic shows the long-range neuronal sprouting that occurs with psilocybin. Image (a) is an untreated brain, while image (b) is a brain on psilocybin.