How to Change Your Mind: The New Science of Psychedelics

by Michael Pollan

The group of tryptamines we call “the classic psychedelics” have a strong affinity with one particular type of serotonin receptor, called the 5-HT2A. These receptors are found in large numbers in the human cortex, the outermost, and evolutionarily most recent, layer of the brain. Basically, the psychedelics resemble serotonin closely enough that they can attach themselves to this receptor site in such a way as to activate it to do various things. Curiously, LSD has an even stronger affinity with the 5-HT2A receptor—is “stickier”—than serotonin itself, making this an instance where the simulacrum is more convincing, chemically, than the original. This has led some scientists to speculate that the human body must produce some other, more bespoke chemical for the express purpose of activating the 5-HT2A receptor—perhaps an endogenous psychedelic that is released under certain circumstances, perhaps when dreaming. One candidate for that chemical is the psychedelic molecule DMT, which has been found in trace amounts in the pineal gland of rats.