Psilocybin, the active compound in magic mushrooms, has shown promise as an effective antidepressant. A recent trial demonstrated its comparable effectiveness to commonly prescribed antidepressant drugs. However, the specific effects of psilocybin on the brain and their duration remain unclear.
To address this, researchers conducted a study on mice and discovered that a single dose of psilocybin induced an immediate and long-lasting increase in neuronal connections. This finding could help explain the compound's antidepressant effects.
Compared to the control group, the mice treated with psilocybin exhibited a significant increase in dendritic spines, which are small protrusions on the neurons that transmit electrical signals and synaptic plasticity. Within 24 hours of receiving a single dose of psilocybin, the mice showed an increase in the density and size of dendritic spines, which persisted for several days. Even after 34 days, about a third of the newly formed spines were still present.
Interestingly, the distribution of the new dendritic spines varied among the mice. Some dendrites retained all the newly formed spines, while others lost them completely, although the implications of this observation remain unclear.
Behaviorally, the mice treated with psilocybin displayed improved stress-coping mechanisms. When subjected to mild electrical shocks, they exhibited a greater inclination and ability to escape, accompanied by increased neurotransmitter activity.
The researchers compared these effects to ketamine, which increased dendritic spine density. This suggests that rapid structural changes in neurons may be a key factor in the antidepressant effects of drugs like ketamine and serotonergic psychedelics.
Although it remains unclear why compounds that act differently on the brain produce similar effects, further investigation is warranted. Overall, this research contributes to our understanding of the mechanisms behind the antidepressant properties of psilocybin and underscores its potential as a novel treatment for depression.