The Reptile Brain’s Waking Dreams

Jeff Warren contemplates the science behind the powerful Amazonian hallucinogen, ayahuasca:

We began to discuss the origin of our visions. I suggested the most prudent explanation lay with the brain’s chemistry and the intersection of the drug’s two active agents. One plant boosts the amount of serotonin in the body, creating a hyper-alert ecstatic feeling, while the other boosts the amount of DMT, a naturally-occurring brain chemical thought to play a role in REM sleep. “Thus,” I said, “the serotonin circle overlaps with the DMT circle, and we sit in the middle, submerged in a waking dream.” … Michael, a well-known anthropologist and author, shared his own theory. Psychedelics, he explained, acted as “psycho-integrators,” linking up three evolutionary layers of the brain: the ancient reptilian brain stem, the middle-aged mammalian limbic system and the relatively modern frontal cortex. Ayahuasca, he told the group, rerouted habitual ways of thinking down through the primitive brain stem. “That’s why you can’t put so many of these experiences into words,” he said. “The reptile brain stem can’t make words. It’s pre-verbal.”

The Dish’s earlier psychedelic thread is here.