Psilocin has a chemical structure that is very similar to the neurotransmitter serotonin that is naturally occurring in the body. Neurotransmitters are chemicals that neurons use to communicate with each other. When the levels of serotonin are changed, they will affect sleep, appetite, sensory perception, temperature regulation, pain suppression, and mood.
Serotonin is absorbed by neurons at receptor sites known as the 5-HT receptors. Psilocin's chemical structure is very similar to serotonin, and is taken up by the 5-HT2 receptor site, one of the many receptor types.
After the psilocin molecules bind with the 5-HT2 receptor sites, very little is actually known about what happens. There is not enough data to explain clinically exactly what the effects of the active ingredients in magic mushrooms (shrooms). What we do know is that psilocin is NOT physically harmful to the body or brain.
So basically, psilocin molecules from the magic mushrooms bing with serotonin receptor sites in the brain and cause the mind to do strange things and no one, not even scientists, are really sure why.