If you’ve ever had the chance to experience a magic mushroom or truffle trip, then we don’t need to explain to you just how extraordinary it can be. Today, we know all too well that magic mushrooms can take you on quite a trip and show you a completely different reality. But that wasn’t always the case. The first types of mushrooms weren’t psychedelic at all. Scientists now believe they finally understand how and why these fungi began producing their most remarkable active compound: psilocybin.
Little knowledge about psilocybin
Scientists with a passion for hallucinogens had a field day in the 1950s and 1960s. Drugs such as LSD and psilocybin—the active ingredient in magic mushrooms—were completely legal, and researchers could easily obtain them, resulting in several hundred promising studies. That came to a halt in the 1970s, however, when Richard Nixon signed the Controlled Substances Act. It completely banned the use, sale, and transport of psychedelics and stifled research into them. “It was expected that you could kiss your career goodbye if you researched psychedelics,” says Jason Slot of Ohio State University.
And he found that regrettable. He tried magic mushrooms himself as a young adult, with astonishing results. “It helped me think more fluidly, with fewer assumptions or acquired limitations,” he says. “And I developed a greater sensitivity to natural patterns.” That ability inspired him to study evolution, but he eventually became a mycologist—someone who knows everything about fungi. Now it is precisely this man who decided to combine the two and investigate where psilocybin actually comes from. “I realized how little we still know about the genetics and ecology of such a historically significant substance,” he explains.
Closely related fungal species
It’s possible that mushrooms independently developed the ability to produce psilocybin. It’s also possible that all mushrooms once did so, and that most of them have lost that ability. Yet Slot believed neither explanation was likely. Instead, he suspected that the genes for producing psilocybin had jumped between different species.
To investigate this, biologists from Ohio State University and the University of Tennessee studied a group of mushrooms that all produced psilocybin but were not related to one another.They discovered that all the genes responsible for producing the substance are highly similar. These genes were even more similar than others found in closely related fungal species.
This observation suggests that these genetic traits were not inherited from a common ancestor, but rather were directly transferred between distantly related species. A phenomenon known as "horizontal gene transfer" (or HGT). This can occur through various processes, such as viruses carrying genes from one species to another.
The role of psilocybin in nature
But one question remained: “What is the role of psilocybin in nature?” Well, experts believe the phenomenon occurs in nature as a response to stressors or to enable survival in various conditions. Based on this hypothesis, Jason Slot and his colleagues discovered a clue: the genes responsible for producing psilocybin appeared to have migrated to an environment with many mushroom-eating insects. An observation that took on new meaning by focusing on the effects of the substance.
Once inside the body, psilocybin interferes with a specific neurotransmitter and disrupts its function. We know that this causes the most bizarre hallucinations in humans, but in insects it has another interesting effect: it reduces their appetite. "We believe that fungi have evolved into hallucinogens because it reduces the chance of them being eaten by insects," explains Jason Slot. "Psilocybin probably doesn’t just taste bad. In a sense, the fungi alter the ‘mind’ of insects to serve their own needs,” he says.
The substance would thus serve as a survival mechanism. Today, however, the effect is having the opposite result: magic mushrooms are more popular than ever!
