Yale University researchers have found that a single dose of psilocybin a serotonergic psychedelic can cause an increase in the number of neuronal connections in mice. A finding that cautiously encourages the use of this treatment in major depressive disorder.
Psychedelic drugs, such as LSD and psilocybin (found in magic mushrooms) are substances that induce an altered state of consciousness. They have long been recognized as having therapeutic potential in neuropsychiatric disorders, including depression, obsessive-compulsive disorder, and substance abuse.
Among this family of psychedelics, studies since 2016 have shown that psilocybin an alkaloid found in some hallucinogenic mushrooms relieves symptoms of depression quickly and with lasting benefits over several months.
As a result of these findings, the Food and Drugs Administration (FDA) has granted psilocybin “breakthrough therapy” status for the treatment of depressive illness in 2019 and has also decided to begin further clinical trials.
In a new study, Yale researchers showed that a single dose of psilocybin administered to mice caused an immediate and sustained increase in connections between neurons in the spinal column and the medial frontal cortex. The results were published in the journal Cell-Neuron.
The potential of psilocybin
Previous studies have found synaptic atrophy in the prefrontal cortex of patients suffering from depression or chronic stress, that is, a reduction in the number of neuronal connections. This is a significant loss, which contributes to the development of cognitive, emotional, and memory disorders. Knowing this, the study focused on psilocybin’s ability to increase the density of dendritic spines – tiny protrusions found on nerve cells that facilitate the transfer of information between neurons.
Using chronic two-photon microscopy, the researchers observed the famous dendritic spines in live mice over several days. They found an increase in the number of dendritic spines and their size within 24 hours of psilocybin administration. “Not only did we see a 10 percent increase in the number of neuronal connections, but they were on average about 10 percent larger, so the connections were also stronger,” says Alex Kwan, professor of psychiatry and neuroscience at Yale and lead author of the study. What’s more, these changes were still present a month later.
However, the study specifies that it is not yet possible to know whether these results can be extrapolated to humans. Caution is advised.