magic-mushrooms effect on brain.

Magic mushrooms are hallucinogens

Hallucinogens powerfully affect the brain, distorting the way our
five senses work and changing our impressions of time and space. People
who use these drugs a lot may have a hard time concentrating, communicating,
or telling the difference between reality and illusion.

How Hallucinogens Affect Your Senses

Your brain controls all of your perceptions — the way you see, hear,
smell, taste, and feel. How does your brain communicate with the rest
of your body? Chemical messengers transmit information from nerve cell
to nerve cell in the body and the brain. Messages are constantly being
sent back and forth with amazing speed.

Your nerve cells are called neurons, and their chemical messengers are
called neurotransmitters. When neurotransmitters attach to special places
on nerve cells (called receptors), they cause changes in the nerve cells.

This communication system can be disrupted by chemicals like hallucinogens,
and the results are changes in the way you sense the world around you.

More specificly the Psilocybin chemical reaction on brain

Psilocin, the active metabolite of psilocybin, acts by interaction with
neurotransmitter receptors on nerve cells in the brain where it mimicks
the action of serotonin (5-HT). Specifically, psilocin is a post-synaptic
5-HT2A receptor agonist. This is the same mechanism of action as for the
other hallucinogens like LSD, mescaline, or 2C-B. LSD and psilocybin show
cross-tolerance — after taking one of these substances, the brain
quickly develops a tolerance to it, and taking another dose of either
soon afterward will require more than usual to achieve the desired effects.

Psilocybin and medicine

Psilocybin has been studied as a treatment for several disorders.

In the US, an FDA-approved study supported by MAPS (Multidisciplinary
Association for Psychedelic Studies) began in 2001 to study the effects
of psilocybin on patients with obsessive-compulsive disorder. MAPS has
also proposed studying psilocybin’s potential application for the treatment
of cluster headaches based on anecdotal evidence presented to them by
a cluster headache sufferer.