Thought I would revive this thread...
For those interested Erowid posted a fairly detailed discussion of the facts in 2010:
Ask Erowid Question and Answer: Is DMT produced in the human brain?
www.erowid.org
Here is a link to a poster from Nicholas Cozzi. It used INMT antibodies to probe INMT presence in CNS and spinal cord in three different (non-human) primates. INMT immunoreactivity was observed in various CNS regions in all three species.
Link for the poster:
N,N-dimethyltryptamine (DMT) is a naturally-occurring indole hallucinogen found in plants, animals, and humans, but its biological role has not been fully characterized. DMT has been proposed to act as a neurotransmitter in humans and to be involved
www.academia.edu
This is his current abstract for this poster for the MAPS 2013 conference:
Indolethylamine N-methyltransferase Expression in Primate Nervous Tissue
Nicholas Cozzi
N,N-dimethyltryptamine (DMT) is a naturally-occurring indole hallucinogen found in plants, animals, and humans, but its biological role has not been fully characterized. DMT has been proposed to act as a neurotransmitter in humans and to be involved in psychosis, dreaming, near-death experiences, and spiritual exaltation. DMT is biosynthesized from tryptamine through the actions of the enzyme indolethylamine N-methyltransferase (INMT). Using S-adenosyl methionine as the methyl donor, INMT catalyzes the addition of methyl groups to tryptamine and analogous indole alkylamines.
Human INMT was cloned and sequenced in 1999. Assessment of human INMT expression by Northern blot analysis in 35 tissues revealed widespread INMT mRNA distribution with high levels in thyroid, adrenal gland, and lung. However, in the central nervous system, INMT mRNA was detected only in the spinal cord, but not in whole brain or in seven brain subregions. This observation suggested that INMT may not be involved in DMT biosynthesis in the brain and calls into question the role, if any, of endogenous DMT in producing exceptional mental states. To explore the possibility that INMT is expressed in nervous tissue but that in some situations, INMT mRNA is not detectable by Northern analysis (e.g. the INMT gene is inducible, INMT expression is limited to specific brain nuclei, or INMT mRNA in brain is short-lived), we probed three primate nervous system tissues with antibodies to INMT itself. The antibodies were generated against the C-terminus of human INMT during the original cloning of the human INMT gene. Rhesus macaque spinal cord, pineal gland, and retina were probed with rabbit polyclonal antibodies to human INMT and with mouse antibodies to synaptophysin and synaptotagmin. Nuclear DNA was visualized with 4',6-diamidino-2-phenylindole (DAPI). Binding of primary antibodies to the tissues was visualized with fluorescent goat anti-rabbit and goat anti-mouse secondary antibodies. All three of the nervous tissues tested were positive for INMT immunoreactivity. In agreement with earlier Northern studies in human tissue, INMT immunoreactivity was detected in spinal cord where it was localized in ventral horn motoneurons. In the pineal gland, the INMT signal was robust and punctuate but did not colocalize with synaptophysin, synaptotagmin, or DAPI. Strong INMT immunoreactivity was detected in retinal ganglion neurons and at synapses in the inner and outer plexiform layers. We conclude that INMT protein is expressed in some primate central nervous system tissues, but whether INMT expression is associated with the biosynthesis of DMT in neurons remains to be investigated.
Here is a link to a great talk Nick gave at the MAPS 2010 conference.
He shows DMT is released from PC12 cells upon electro-induced depolarization using patch amperometry.
A great recent review on the presence of detection of endogenous DMT was also published in Drug Testing and Analysis by Barker McIlhenny and Strassman. I do not have acess to the full text to post currently but here is a link:
