Biosynthesis and Extracellular Concentrations of N,N-dimethyltryptamine (DMT) in Mammalian Brain.
Level 5 - mechanism / opinion, no new human data
Preclinical animal experiment and post-mortem tissue analysis
PubMed 31249368 · doi:10.1038/s41598-019-45812-w
What was done
Researchers investigated whether N,N-dimethyltryptamine (DMT) is biosynthesized in the mammalian brain. Using in situ hybridization, they evaluated indolethylamine-N-methyltransferase (INMT) transcript expression in rat and human cerebral cortex, pineal gland, and choroid plexus, and tested for colocalization with aromatic-L-amino acid decarboxylase (AADC) mRNA in rat brain and periphery. Extracellular DMT concentrations were measured in the cerebral cortex of behaving rats (intact and pinealectomized) under basal conditions and following experimental cardiac arrest.
What was found
INMT transcripts were identified in the cortex, pineal gland, and choroid plexus of both rats and humans. INMT and AADC mRNA colocalized in rat brain tissues, with minimal overlap in peripheral tissues. Basal extracellular DMT concentrations in rat cortex were comparable to canonical monoamine neurotransmitters like serotonin, both with and without an intact pineal gland. Experimental cardiac arrest induced a significant increase in DMT levels in the rat visual cortex, which also occurred independently of the pineal gland. Specific numeric concentrations were not reported in the abstract.
Why it matters
This study provides evidence that the rodent brain expresses the machinery necessary to synthesize DMT locally and release it extracellularly at physiological levels without requiring the pineal gland.
Limits
Functional in vivo microdialysis and cardiac arrest experiments were conducted only in rats; human data were limited to static transcript detection in tissue. Sample sizes and exact quantitative concentration values were not provided in the abstract.
Cited by
- context The human brain releases DMT at birth and upon death.
- supports DMT is naturally present in small amounts in the brain.