AbstractN,N-dimethyltryptamine (DMT), a psychedelic compound identified endogenously in mammals, is biosynthesized by aromatic-L-amino acid decarboxylase (AADC) and indolethylamine-N-methyltransferase (INMT). Whether DMT is biosynthesized in the mammalian brain is unknown. We investigated brain expression of INMT transcript in rats and humans, co-expression of INMT and AADC mRNA in rat brain and periphery, and brain concentrations of DMT in rats. INMT transcripts were identified in the cerebral cortex, pineal gland, and choroid plexus of both rats and humans viain situhybridization. Notably, INMT mRNA was colocalized with AADC transcript in rat brain tissues, in contrast to rat peripheral tissues where there existed little overlapping expression of INMT with AADC transcripts. Additionally, extracellular concentrations of DMT in the cerebral cortex of normal behaving rats, with or without the pineal gland, were similar to those of canonical monoamine neurotransmitters including serotonin. A significant increase of DMT levels in the rat visual cortex was observed following induction of experimental cardiac arrest, a finding independent of an intact pineal gland. These results show for the first time that the rat brain is capable of synthesizing and releasing DMT at concentrations comparable to known monoamine neurotransmitters and raise the possibility that this phenomenon may occur similarly in human brains.

This report provides a historical overview of research concerning the endogenous hallucinogen N, N-dimethyltryptamine (DMT), focusing on data regarding its biosynthesis and metabolism in the brain and peripheral tissues, methods and results for DMT detection in body fluids and brain, new sites of action for DMT, and new data regarding its possible physiological and therapeutic roles. Research that further elaborates its consideration as a putative neurotransmitter is also addressed. Taking these studies together, the report proposes several new directions and experiments to ascertain the role of DMT in the brain, including brain mapping of enzymes responsible for the biosynthesis of DMT, further studies to elaborate its presence and role in the pineal gland, a reconsideration of binding site data, and new administration and imaging studies. The need to resolve the "natural" role of an endogenous hallucinogen from the effects observed from peripheral administration are also emphasized.

N, N-dimethyltryptamine (DMT) is an indole alkaloid produced by a number of plants and animals, including humans. Its psychoactive effects were first described in 1956 by Stephen Szára, but have been exploited for centuries by South American indigenous populations in the form of ayahuasca. In the present review, we assess the state of the art regarding a putative role for endogenous DMT and potential clinical applications of ayahuasca and DMT. A review assessing the pharmacological profile of DMT and its clinical effects in humans was performed using the PubMed data base until 5 August 2018 with the words: ayahuasca and N,N-dimethyltryptamine. While the role of endogenous DMT remains unclear, ayahuasca has promising results in anxiety, depression and substance dependence. Since ayahuasca has a good safety profile, it is crucial to conduct further research aimed at developing new treatments for psychiatric disorders.

Abstract 5-Methoxy-N,N-dimethyltryptamine (acronymized as 5-MeO-DMT) is sui generis among the numerous naturally-occurring psychoactive substances due to its unparalleled ego-dissolving effects which can culminate in a state of nondual consciousness (which is phenomenologically similar to transformative peak experiences described in various ancient contemplative traditions, e.g., Advaita Vedānta, Mahāyāna Buddhism). The enigmatic molecule is endogenous to the human brain and has profound psychological effects which are hitherto only very poorly understood due to the absence of scientifically controlled human experimental trials. Its exact neuronal receptor binding profile is a matter of ongoing scientific research, however, its remarkable psychoactivity is presumably mediated via agonism of the 5-HT 2A (serotonin) receptor subtype. Anthropological/ethnopharmacological evidence indicates that various cultures utilized 5-MeO-DMT containing plants for medicinal, psychological, and spiritual purposes for millennia. In this paper we argue that this naturally occurring serotonergic compound could be fruitfully utilized as a neurochemical research tool which has the potential to significantly advance our understanding of the cognitive and neuronal processes which underpin cognition and creativity (downregulation of the default-mode network, increased neuronal functional connectivity, etc.). An eclectic interdisciplinary perspective is adopted, and we present converging evidence from a plurality of sources in support of this conjecture. Specifically, we suggest that 5-MeO-DMT has great potential in this respect due to its incommensurable capacity to completely disintegrate self-referential cognitive/neuronal processes (viz., “ego death”). The importance of unbiased systematic scientific research on naturally occurring endogenous psychoactive compounds is discussed from a Jamesian radical empiricism perspective and potential scenarios of abuse are discussed (particularly in the context of military torture).

The human body possesses enzymatic machinery to both synthesize and rapidly degrade N,N-dimethyltryptamine (DMT). This coexistence raises a question: does DMT serve an endogenous function, or is it a metabolic byproduct with no physiological role? DMT is structurally almost identical to serotonin and binds to the same serotonin receptors. Serotonin is universally accepted as a neurotransmitter with essential functions. If DMT were merely a metabolic byproduct, why would the body produce a molecule shaped like serotonin and binding to serotonin receptors through regulated enzymatic steps? This paper critically evaluates the hypothesis that DMT is an endogenous molecule with physiological functions. The evidence is mixed and contested. Barker (2025) reports DMT concentrations in the nM range, comparable to serotonin and dopamine. Palner et al. (2026) report that DMT is below the detection limit in rat brain. The sigma-1 receptor affinity (Ki ~14 μM) is three orders of magnitude higher than reported physiological concentrations. The intracellular 5-HT2A receptor finding (Barker 2025) has not been independently replicated. The dietary DMT gap has not been directly measured. Clinical trials demonstrate that high-dose DMT produces antidepressant effects (Erritzoe et al. 2026; Falchi-Carvalho et al. 2025), but clinical efficacy does not establish endogenous function. Based on this critical evaluation, a companion paper (Solis, 2026b) proposes and evaluates a focused hypothesis: that DMT maintains neuroplasticity, and that its decline may contribute to age-related cognitive decline. The present paper outlines a research program to test whether DMT has physiological functions, while acknowledging that the prior probability of endogenous function may be low given the current state of the evidence.

(October 1977). "The in vitro identification of dimethyltryptamine (DMT) in mammalian brain and its characterization as a possible endogenous neuroregulatory Dimethyltryptamine (DMT), also known as N,N-dimethyltryptamine (N,N-DMT), is a serotonergic hallucinogen and investigational drug of the tryptamine family that occurs naturally in many plants and animals. DMT is used as a psychedelic drug and prepared by various cultures for ritual purposes as an entheogen. DMT has a rapid onset, intense effects, and a relatively short duration of action. For thos Dimethyltryptamine (DMT), also known as N,N-dimethyltryptamine (N,N-DMT), is a serotonergic hallucinogen and investigational drug of the tryptamine family that occurs naturally in many plants and animals. DMT is used as a psychedelic drug and prepared by various cultures for ritual purposes as an entheogen. DMT has a rapid onset, intense effects, and a relatively short duration of action. For those reasons, DMT was known as the "businessman's trip" during the 1960s in the United States, as a user could access the full depth of a psychedelic experience in considerably less time than with other substances such as LSD or psilocybin mushrooms. DMT can be inhaled or injected and its effects depend on the dose, as well as the mode of administration. When inhaled or injected, the effects last about five to fifteen minutes. Effects can last three hours or more when orally ingested along with a monoamine oxidase inhibitor (MAOI), such as the ayahuasca brew of many native Amazonian tribes. DMT induces intense, often indescribable subjective experiences involving vivid visual hallucinations, altered sensory perception, ego dissolution, and encounters with seemingly autonomous entities. DMT is generally considered non addictive with low dependence and having little to no tolerance build-up with short-acting routes, but it may cause acute psychological distress or cardiovascular effects, especially in predisposed individuals. DMT was first synthesized in 1931. It is a functional and structural analog of other psychedelic tryptamines such as 4-AcO-DMT (O-acetylpsilocin), psilocybin (4-PO-DMT), psilocin (4-HO-DMT), O-methylbufotenin (5-MeO-DMT), and bufotenin (5-HO-DMT). Parts of the structure of DMT occur within some… A 2013 study found DMT in microdialysate obtained from a rat's pineal gland, providing evidence of endogenous DMT in the mammalian brain. In 2019, experiments showed that the rat brain is capable of synthesizing and releasing DMT. These results raise the possibility that this phenomenon may occur similarly in human brains. Quantities of dimethyltryptamine and O-methylbufotenin were found present in the cerebrospinal fluid of humans in a 1978 psychiatric study.

pregnenolone sulfate, dimethyltryptamine (DMT) and dehydroepiandrosterone sulfate (DHEA-S) bind to the σ1 receptor. The mammalian σ1 receptor is an integral membrane The sigma-1 receptor (σ1R), one of two sigma receptor subtypes, is a chaperone protein at the endoplasmic reticulum (ER) that modulates calcium signaling through the IP3 receptor. In humans, the σ1 receptor is encoded by the SIGMAR1 gene. The σ1 receptor is a transmembrane protein expressed in many different tissue types. It is particularly concentrated in certain regions of the central nervous The…