The psychedelic drug Psilocybin, a naturally occurring compound found in some mushrooms, has been studied as a potential treatment for depression for years.
In a new study published in the journal Neuron, Yale researchers show that a single dose of psilocybin given to mice promoted an immediate and long-lasting increase in the connections between neurons.
Psilocybin is a serotonergic, psychedelic with untapped therapeutic potential. It is a hallucinogenic substance people often ingest from certain types of mushrooms that grow in regions of Europe, South America, Mexico, and the United States. Psychedelics have been found to produce neural adaptations, although the extent and timescale of the impact in a mammalian brain are unknown.
Researchers used chronic two-photon microscopy to image longitudinally the apical dendritic spines of layer 5 pyramidal neurons in the mouse medial frontal cortex.
“We not only saw a 10% increase in the number of neuronal connections, but also they were on average about 10% larger, so the connections were stronger as well”, said Yale's Alex Kwan, associate professor of psychiatry and of neuroscience and senior author of the study.
Previous laboratory experiments has shown promise that psilocybin, as well as the anaesthetic ketamine, can decrease depression. The new Yale research found that these compounds increase the density of dendritic spines, small protrusions found on nerve cells which aid in the transmission of information between neurons. Chronic depression and stress are known to reduce the numbers of these neuronal connections.
The ritual use of Psilocybin for mystical or spiritual purposes dates back to pre-Columbian Mesoamerican societies and continues to this day. Psilocybin is often used recreationally at dance clubs or by select groups of people seeking a transcendental spiritual experience.