A psychedelic Amazonian drink called ayahuasca has been found to promote the birth of new brain cells in the hippocampus, a part of the brain that is largely responsible for memory and learning. While the brew has been used as a spiritual sacrament for thousands of years by indigenous communities, its role as a potential treatment for neurological and emotional disorders has caused a major spike in interest within the Western scientific community in recent years.
Ayahuasca contains the psychoactive compound N, N-dimethyltryptamine (DMT), which is known to produce intense visions and hallucinations. Yet it also contains compounds like harmine and tetrahydroharmine, both of which have previously been found to stimulate the formation of neurons from stem cells in a petri dish.
Obviously, though, there’s a pretty big difference between a sterilized dish and an actual brain, which is why researchers at the Complutense University of Madrid have spent the past few years trying to figure out if the visionary brew can also spark the birth of new neurons in living hippocampi. Publishing their findings in the journal Translational Psychiatry, the study authors reveal that not only did ayahuasca promote neurogenesis in mice during their experiments, but that these rodents also performed better on memory tasks than those that had not been treated with the trippy beverage.
Neurogenesis consists of three main phases, beginning with the proliferation of neuronal stem cells to form neuroblasts in the subgranular zone (SGZ) of the dentate gyrus, which is found within the hippocampus. Next, these neuroblasts must migrate into the granular layer of the hippocampus, before differentiating into functional neurons. To determine how ayahuasca influences this process, the researchers injected the brew into the brains of mice before removing and analyzing their hippocampi.
Results showed that this caused neuronal stem cells within the SGZ to proliferate and differentiate into neurons, as well as neuronal support cells such as astroglia and oligodendrocytes. To determine whether these cells were able to migrate into the granular and become functional, the study authors injected a second group of mice with ayahuasca over a period of three weeks, before presenting them with a range of tasks that are designed to assess memory and learning.
The fact that the rodents performed better at these tasks after receiving a course of ayahuasca treatment suggests that the newly-formed neurons had indeed become functional, boosting the animals’ cognitive abilities.
According to the study authors, this finding could open the door to new treatments for neurodegenerative diseases like dementia, which are characterized by a loss of neurons in key brain areas. “The challenge is to activate our dormant capacity to form neurons and thus replace the neurons that die as a result of the disease,” explained study author José Ángel Morales in a statement. “This study shows that DMT is capable of activating neural stem cells and forming new neurons.”
Furthermore, while ayahuasca’s psychedelic effects are mediated by serotonin receptors in the brain, the study authors found that the brew stimulates neurogenesis by interacting with a different receptor known as sigma-1. This is significant, as it suggests that it may be possible to trigger the formation of new neurons without tripping out.
In other words, by developing medications that bind only to sigma-1 receptors without interacting with serotonin receptors, the next generation of treatments for dementia could stimulate the formation of new neurons without sending patients on any mind-bending cosmic adventures.