A new study conducted by researchers at the University of Southern Denmark has found no evidence of N,N-dimethyltryptamine (DMT) occurring naturally in the brains of rats, challenging a long-held theory about the origins of altered states of consciousness. The findings, published earlier this month, cast doubt on the idea that the brain synthesizes the psychedelic compound, often referred to as the “spirit molecule,” for use in dreaming or near-death experiences.
For decades, the hypothesis that the human brain produces DMT has been a prominent element in psychedelic research and popular culture. Proponents suggested the substance might act as a signaling molecule within the brain, potentially alongside serotonin. Though, the recent research, utilizing highly sensitive quantitative methods, detected no detectable levels of DMT in the rat brain, even when the enzymes responsible for breaking down the compound were inhibited. This suggests that if DMT does play a role in brain function, it does not operate within the classical serotonin system as previously thought.
The study specifically examined whether DMT could be stored in serotonin-releasing nerve terminals. Researchers found no evidence of accumulation within these terminals, further diminishing the likelihood of DMT functioning as a co-transmitter. The team employed trace-detection methods designed to identify even minute quantities of the substance, but the results remained consistently negative, according to the published findings.
Whereas mammals possess the enzyme indole N-methyltransferase (INMT), which is capable of synthesizing DMT, the study demonstrates that the presence of this enzyme does not necessarily equate to active DMT production within the brain. This distinction is crucial, as previous assumptions often linked the existence of INMT to the automatic production of DMT.
The research does not entirely dismiss the possibility of DMT being present in other tissues or physiological states, such as during birth or death. However, it clarifies that DMT is not a standard signaling substance within the brain.
Interestingly, a separate study, published February 4th in the Journal of Neuroscience, found that intravenous administration of DMT did cause dose-dependent increases in serotonin and dopamine levels in the medial prefrontal and somatosensory cortices of rats, alongside changes in gamma functional connectivity. This preprint study, which has not yet undergone peer review, highlights the neurochemical effects of externally administered DMT, but does not contradict the recent findings regarding endogenous production. The earlier study used intravenous administration, delivering the compound directly into the bloodstream, a method distinct from investigating naturally occurring levels within brain tissue.
Further research suggests DMT may be involved in brain development in rat pups, according to data published in ScienceDirect. However, the current study focused on adult rats, and the role of DMT in developmental stages remains an open question.
