Rat brains do release measurably higher levels of DMT during cardiac arrest, according to the only direct experimental evidence available. But that finding comes from rodent research, and nobody has measured DMT surging in a dying human brain. The idea that a flood of endogenous DMT explains near-death experiences is one of the most captivating hypotheses in consciousness research, yet it remains far from proven. The gap between a detectable spike in a rat’s visual cortex and the vivid tunnels of light reported by people who nearly die is wider than popular accounts suggest.
What the Rat Studies Actually Showed
The landmark experiment behind the claim was published in 2019 by a team at the University of Michigan. Researchers confirmed that the mammalian brain possesses the enzymatic machinery to produce DMT on its own. Using tissue from both rats and humans, they found that the gene for indolethylamine-N-methyltransferase (the enzyme that catalyzes DMT synthesis) was active in the cerebral cortex, pineal gland, and choroid plexus. Crucially, the gene’s transcript overlapped in rat brain tissue with another enzyme needed to complete the synthesis pathway, meaning the brain had the tools to build DMT locally rather than importing it from elsewhere in the body.1PubMed Central. Biosynthesis and Extracellular Concentrations of N,N-dimethyltryptamine (DMT) in Mammalian Brain
Under normal conditions, DMT was present in rat brain tissue at very low concentrations, averaging around half a nanomolar. When the researchers induced cardiac arrest in the rats, DMT levels in the visual cortex rose significantly. The concentrations reached were comparable to those of well-known neurotransmitters like serotonin and dopamine. That last detail is what grabbed headlines: if DMT reaches the same ballpark as everyday signaling molecules, maybe it does something meaningful during the dying process.1PubMed Central. Biosynthesis and Extracellular Concentrations of N,N-dimethyltryptamine (DMT) in Mammalian Brain
The study was rigorous for what it set out to do, but it has limits. It measured extracellular DMT in a small region of the rat brain using microdialysis probes, a technique that samples fluid from a tiny area. Whether similar surges happen throughout the whole brain, or whether they happen in human brains at all, remains unknown. Rats are useful models, but the leap from rodent neurochemistry to human subjective experience is enormous.
The Pineal Gland Myth
Much of the popular fascination with dying-brain DMT traces back to Rick Strassman’s 2001 book “DMT: The Spirit Molecule,” which speculated that the pineal gland might release a massive dose of DMT at the moment of death. The pineal gland has a long history of mystical associations, and the hypothesis had an almost irresistible narrative appeal: a tiny structure buried deep in the brain, already linked to melatonin and sleep, quietly holding the key to visions of the afterlife.
The 2019 rat study actually undermined this idea. The researchers found that removing the pineal gland from rats did not prevent the surge in brain DMT during cardiac arrest. The increase occurred regardless of whether the pineal gland was intact. While the pineal gland does express the genes needed for DMT production, the cortex itself appears to be a more relevant source during the dying process.1PubMed Central. Biosynthesis and Extracellular Concentrations of N,N-dimethyltryptamine (DMT) in Mammalian Brain
This matters because it reshapes how we think about the mechanism. If the cortex is producing DMT locally in response to extreme stress rather than receiving a bolus from the pineal gland, the chemistry becomes more diffuse and harder to study. It also makes the “massive flood” narrative less plausible. Local production in scattered cortical neurons is a different thing from a single gland dumping a concentrated payload into the bloodstream.
The Concentration Problem
Even if the brain does produce more DMT during cardiac arrest, the central question is whether it produces enough to cause anything resembling a psychedelic experience. When someone smokes or is injected with DMT, the doses involved are measured in milligrams, and the drug reaches the brain in high concentrations all at once. The levels measured in dying rat brains, while elevated, were in the nanomolar range.
There is an interesting wrinkle, though. Recent research suggests DMT may not need to reach the same concentrations as an externally administered dose to have biological effects. Because DMT is fat-soluble, it can cross cell membranes and activate receptors inside cells rather than just on their surfaces. This intracellular activity, particularly at sigma-1 receptors and possibly at serotonin 2A receptors located inside neurons, might mean DMT has effects at lower concentrations than would be needed if it only worked through conventional signaling at the cell surface.2PubMed. Exploring DMT: Endogenous role and therapeutic potential
Still, the honest assessment is that we do not know whether the concentrations observed in rat cortex would be enough to trigger any subjective experience in a human, let alone the elaborate visions described in near-death accounts. This is the weakest link in the chain of reasoning. Without human brain data measured in real time during cardiac arrest, the hypothesis stays in the realm of plausible-but-unconfirmed.
How DMT Experiences Resemble Near-Death Experiences
One line of evidence people cite in favor of the DMT hypothesis is the phenomenological overlap between DMT trips and near-death experiences. If both produce similar subjective states, maybe they share a common cause. Researchers have tested this more carefully than you might expect.
A 2018 study gave DMT to healthy volunteers and then had them fill out a standard near-death experience questionnaire. The total NDE scores from the DMT sessions were statistically comparable to scores from people who had reported actual near-death experiences. The overlap was striking enough that the researchers titled their paper “DMT Models the Near-Death Experience.”3PubMed Central. DMT Models the Near-Death Experience
A more recent study pushed this further by comparing both types of experience within the same individuals, people who had survived a near-death event and also later used psychedelics. The two experiences overlapped significantly on mystical-type effects, feelings of deep insight, and the sense of encountering a reality more “real” than everyday life. But the differences were informative too: near-death experiences scored higher on feelings of disembodiment, while psychedelic experiences scored higher on visual imagery and sensory effects.4PubMed Central. Within-subject comparison of near-death and psychedelic experiences: acute and enduring effects
The similarity is real, but it does not prove that DMT causes near-death experiences. Two experiences can feel alike because they activate overlapping brain networks without sharing a single chemical trigger. A fever dream and a psychedelic trip can both feel intensely real and emotionally charged, but no one argues they have the same pharmacology.
What Else Might Explain Near-Death Experiences
The DMT hypothesis is only one of several neurobiological explanations for what happens during the dying process. Some of the competing accounts have stronger direct evidence in humans.
The most striking alternative involves gamma-wave surges. In 2013, researchers at the University of Michigan recorded brain activity in rats during cardiac arrest and found a paradoxical burst of high-frequency gamma oscillations within the first 30 seconds after the heart stopped. These gamma waves were globally coherent across the brain and showed stronger connectivity patterns than during normal waking consciousness.5PubMed Central. Surge of neurophysiological coherence and connectivity in the dying brain A related study found that asphyxia also triggered a broad release of neurotransmitters alongside these connectivity surges, and that the brain’s cortex actually began sending signals to the heart that may accelerate the onset of fatal arrhythmia.6PubMed Central. Asphyxia-activated corticocardiac signaling accelerates onset of cardiac arrest
In 2023, the same research group reported that this phenomenon occurs in humans too. Analyzing brain recordings from four comatose patients who died after withdrawal of life support, they found that two of the four showed a rapid surge of gamma power and increased connectivity between brain regions during the dying process.7PubMed Central. Surge of neurophysiological coupling and connectivity of gamma oscillations in the dying human brain This is, to date, some of the best evidence that the dying human brain can enter a state of heightened neural activity rather than simply fading out. Whether that activity produces conscious experience is unknown, but the finding is consistent with the idea that something vivid could be happening in those final moments.
Another explanation focuses on glutamate and NMDA receptors. During oxygen deprivation, the brain releases a flood of glutamate, which overactivates NMDA receptors and can damage neurons. The brain may respond by releasing its own protective compounds that block these receptors, and that blocking action could produce altered states of consciousness similar to those caused by ketamine, a drug that works through the same receptor system. Karl Jansen laid out this model in detail, pointing out that ketamine reliably produces experiences resembling near-death reports: tunnels, bright light, encounters with entities, feelings of peace and detachment from the body.8Journal of Near-Death Studies. The Ketamine Model of the Near-Death Experience: A Central Role for the N-Methyl-D-Aspartate Receptor
A large-scale computational analysis of written experience reports added weight to the ketamine model. By comparing the language used in thousands of drug-experience reports with descriptions of near-death experiences, researchers found that ketamine produced the closest semantic match to NDE accounts, more so than DMT or any other substance tested.9Consciousness and Cognition. Neurochemical models of near-death experiences: A large-scale study based on the semantic similarity of written reports That finding is worth sitting with for a moment: if you are looking for the drug that best mimics what people describe when they nearly die, the data point to ketamine, not DMT.
The Neuroprotection Angle
If the brain does produce DMT under extreme stress, the reason may have nothing to do with generating visions. A growing body of research suggests DMT has neuroprotective properties, meaning it might help brain cells survive oxygen deprivation.
A 2021 study tested this directly by inducing stroke-like conditions in rat brains and administering DMT. The compound reduced the spread of a damaging electrical wave called spreading depolarization, which fans out through brain tissue during a stroke and kills neurons in its path. DMT also reduced the number of cells undergoing two different forms of cell death and helped astrocytes, the support cells that maintain the blood-brain barrier, survive. These protective effects were mediated through sigma-1 receptors, and blocking those receptors eliminated the benefits.10PubMed. N,N-Dimethyltryptamine attenuates spreading depolarization and restrains neurodegeneration by sigma-1 receptor activation in the ischemic rat brain
This reframes the question in an interesting way. Rather than asking “does the brain release DMT to create a farewell hallucination,” a more biologically grounded question might be “does the brain release DMT as part of an emergency response to protect itself?” If the answer is yes, any subjective experience that comes along for the ride might be a side effect of a survival mechanism rather than the point of the mechanism itself.
The Narrow Window of Dying
One practical constraint on all of these hypotheses is how quickly the brain shuts down after the heart stops. A review of the clinical literature found that most studies show consciousness is lost and electrical brain activity ceases within about 30 seconds of abrupt circulatory arrest.11PubMed. Time to loss of brain function and activity during circulatory arrest That is an extremely tight window for any neurochemical process to ramp up, flood the brain, bind to receptors, and generate a complex subjective experience.
The gamma-surge data are consistent with this timeline: the burst of coherent activity in rats appeared within those first 30 seconds and then gave way to electrical silence.5PubMed Central. Surge of neurophysiological coherence and connectivity in the dying brain Whether 30 seconds of heightened brain activity is enough to produce the elaborate narrative experiences people report after being resuscitated is genuinely unclear. Time perception is notoriously distorted under extreme conditions, so a few seconds of neural activity might subjectively feel much longer. But this remains speculation.
It is also worth noting that many near-death experiences are reported after cardiac events where the person is resuscitated within minutes, meaning their brain was not permanently dying. The neurochemistry of brief cardiac arrest followed by successful resuscitation could differ from what happens during irreversible death in ways that nobody has been able to study.
Why Near-Death Experiences Vary
If a single molecule like DMT were the sole driver of near-death experiences, you might expect those experiences to be relatively uniform across people and cultures. They are not. A cross-cultural review found that while there are common themes, including feelings of peace, encounters with deceased relatives, and movement through darkness or toward light, the specific content varies considerably depending on cultural background, religious belief, and language.12PubMed. Phenomenology of near-death experiences: a cross-cultural perspective
Western accounts tend to feature tunnels and bright lights, while accounts from South Asian traditions more frequently involve encounters with messengers or bureaucratic figures, and some Indigenous accounts emphasize landscapes and ancestors. The fact that the phenomenology shifts with cultural context suggests that whatever the underlying neurobiology is, the content is shaped heavily by prior beliefs and expectations. A purely chemical explanation, whether DMT or glutamate or gamma surges, would need to account for why the same chemistry produces such different narratives in different people.
One framework that attempts to bridge this gap comes from evolutionary biology. A 2021 systematic investigation proposed that near-death experiences share an evolutionary origin with thanatosis, the “playing dead” behavior observed across a huge range of animal species from insects to mammals. The researchers argued that both thanatosis and NDEs represent a last-resort defensive response to life-threatening situations, and that the phenomenological features of NDEs, such as immobility, analgesia, and altered consciousness, overlap with what is seen during death-feigning in animals.13PubMed Central. The evolutionary origin of near-death experiences: a systematic investigation Under this view, the brain’s response to mortal threat is a deeply conserved survival program, and the specific subjective experience layered on top of it is a cultural and cognitive construction.
The Out-of-Body Piece
One of the most commonly reported features of near-death experiences is the sensation of leaving one’s body and observing it from above. This component has its own neuroscience, separate from the DMT question. Research using brain mapping in healthy volunteers found that imagining oneself outside one’s own body selectively activates a brain region called the temporoparietal junction. When this area was disrupted using transcranial magnetic stimulation, volunteers’ ability to mentally transform their body perspective was impaired. And in an epileptic patient whose seizures originated from this same region, the seizure focus was partially activated during mental body transformations that mimicked her spontaneous out-of-body experiences.14PubMed. Linking out-of-body experience and self processing to mental own-body imagery at the temporoparietal junction
This points toward a structural, network-level explanation for at least part of the near-death experience that does not require any particular molecule to be involved. Oxygen deprivation, electrical instability, or abnormal activation patterns in the dying brain could disrupt temporoparietal function and produce the feeling of floating above one’s body. The out-of-body component may be a symptom of failing spatial self-processing rather than evidence of a soul departing or a psychedelic trip beginning.
Taken together, the evidence paints a picture more complicated and more interesting than “your brain squirts DMT when you die.” The brain does make DMT. Levels probably rise during extreme physiological stress. But the dying brain is also surging with gamma oscillations, flooding with glutamate, releasing protective compounds, and losing coherent function in spatial processing areas, all within a window of seconds. Attributing the entire near-death experience to one molecule in that chemical storm gives DMT more credit than the current science supports.