We have previously written about the potential medical applications of psilocybin — a naturally occurring compound found in some mushrooms. Last year, for instance, we shared the findings of a Yale study that showed promising results regarding the effect of magic mushrooms on migraines.

Also coming from researchers at the Yale School of Medicine, a recent study yields new evidence about psilocybin’s impressive potential to produce an immediate and long-lasting increase in connections between neurons in mice.

“We not only saw a 10 percent increase in the number of neuronal connections, but also they were on average about 10 percent larger, so the connections were stronger as well,” said neuroscientist Alex Kwan, a senior author of the paper.

Researchers have previously studied the psychedelic drug psilocybin as a potential treatment for depression. The new Yale research found that these compounds increase the density of dendritic spines — small protrusions found on neurons that aid the transmission of electric signals between nerve cells. Depression is known to reduce the number of these neuronal connections.

Equipped with a laser-scanning microscope, Kwan and his team imaged dendritic spines in high resolution and tracked them for multiple days in living mice. They discovered increases in the number of dendritic spines and in their size within 24 hours of administration of psilocybin. 

What’s particularly promising is that these changes were still present a month later. Additionally, mice subjected to stress showed behavioral improvements and increased neurotransmitter activity after being given psilocybin.

Psilocybin has been used for hundreds of years as a staple of religious ceremonies among Indigenous populations. Due to its psychoactive effects, it is also a popular recreational drug that can produce a profound mystical experience. According to Kwan, it may be the novel psychological effects of psilocybin itself that spurs the growth of neuronal connections.

“It was a real surprise to see such enduring changes from just one dose of psilocybin,” he said.  “These new connections may be the structural changes the brain uses to store new experiences.”

Source study: Neuron — Psilocybin induces rapid and persistent growth of dendritic spines in the frontal cortex