A new study has found that a single dose of psilocybin may produce antidepressant effects by increasing the number of synapses in at the brain and enhancing serotonin signalling.
In the study, which comes out of Denmark, researchers injected pigs with the psychedelic compound psilocybin. Half the pigs had their brains analysed after one day, the other half after seven days.
After one day, it was found that a single dose of psilocybin (0.08 mg/kg) produced a 4.42% increase in a particular marker for neural synapse density known as synaptic vesicle protein 2A (SV2A) in the pigs’ hippocampus.
Additionally, a decrease of serotonin receptors was seen in the pigs’ hippocampus and prefrontal cortex.
Seven days post psilocybin injection, there was significantly higher SV2A density in the hippocampus (+9.24%) and the prefrontal cortex (+6.10%), while there were no longer any differences in serotonin receptor density.
It is known that psilocybin exerts much of its psychedelic effects by stimulating serotonin receptors.
The study authors concluded: “Our findings suggest that psilocybin causes increased persistent synaptogenesis [creation of new synapses] and an acute decrease in 5-HT2AR [serotonin 2A receptor] density, which may play a role in psilocybin’s antidepressant effects.”
Previous research has found that psilocybin rapidly increases the expression of several genes related to neuroplasticity in the rat brain.
And just a couple of months ago, a clinical study found that two sessions of psilocybin-assisted therapy produced significant and lasting antidepressant effects, proving to be more than four times more effective than commonly-prescribed antidepressant drugs.