Scientific reports
June 27, 2019
Jon G Dean, Tiecheng Liu, Sean Huff et al.
111 citations
The psychedelic compound N,N-dimethyltryptamine (DMT) is produced naturally in mammals, but whether it is made in the brain was unclear. This study found that the enzymes needed to synthesize DMT are present in the cerebral cortex, pineal gland, and choroid plexus of both rats and humans. In rat brain tissues, the two key enzymes were found together, unlike in peripheral tissues. DMT concentrations in the cerebral cortex of behaving rats were similar to those of neurotransmitters like serotonin. DMT levels in the visual cortex rose significantly after cardiac arrest, even without the pineal gland. These findings indicate the rat brain can synthesize and release DMT at neurotransmitter-like levels, suggesting human brains might do the same.
Current Biology
December 1, 2023
Nicholas Kolbman, Tiecheng Liu, Peter Guzzo et al.
21 citations
A single intravenous dose of psilocybin reduces mechanical hypersensitivity for 28 days in a rat model of formalin-induced chronic pain, suggesting potential for treating chronic pain conditions. The study addresses a gap in research on psilocybin's effectiveness for chronic pain, as prior work focused on psychiatric disorders and substance abuse. No systematic investigation had previously examined psilocybin's impact on chronic pain indices.
Translational Psychiatry
March 25, 2025
Brian H Silverstein, Nicholas Kolbman, Amanda Nelson et al.
8 citations
Psilocybin alters brain network organization in rats in a dose-dependent manner. Using electroencephalography from 27 cortical sites in 12 rats, the study found that psilocybin disrupted theta-gamma coupling, increased frontal high gamma connectivity and network density, and increased posterior theta connectivity and density. Medium gamma frontoparietal connectivity and behavioral activity showed an inverted-U relationship with dose. These results suggest that high-frequency network organization, decoupled from local theta-phase, may be a key signature of psilocybin-induced altered states of consciousness.
bioRxiv Preprint Server
January 22, 2025
Emma R. Huels, Nicholas Kolbman, Christopher W. Fields et al.
4 citations
preprint
A serotonergic psychedelic, DOI, can reverse general anesthesia and restore wakefulness in rats, even while anesthetics like propofol or isoflurane continue to be delivered. Behavioral arousal was accompanied by recovery of high gamma functional connectivity and restoration of brain network structure. These effects were blocked by a 5-HT2A antagonist, volinanserin, and a non-psychedelic 5-HT2A agonist, lisuride, failed to produce similar results. This provides the first evidence of psychedelic-mediated reversal of general anesthesia and concurrent restoration of brain dynamics associated with normal wakefulness.
bioRxiv (Cold Spring Harbor Laboratory)
February 12, 2024
Brian H Silverstein, Nicholas Kolbman, Amanda Nelson et al.
3 citations
preprint
Psilocybin disrupts the coupling between theta and gamma brain waves in rats and reorganizes brain networks in a dose-dependent manner. Using 27 electrodes across the cortex, the study found that psilocybin increased frontal high gamma connectivity and posterior theta connectivity, as well as network density in those regions. Medium gamma frontoparietal connectivity showed a nonlinear relationship with dose. Theta-gamma phase-amplitude coupling was disrupted. These changes suggest that high-frequency network organization, decoupled from local theta-phase, may be a signature of the altered state of consciousness induced by psilocybin.
Journal of Neuroscience
December 19, 2025
Nicolas G. Glynos, Emma R. Huels, Trent Groenhout et al.
In rats, intravenous DMT causes dose-dependent increases in serotonin and dopamine in the medial prefrontal and somatosensory cortices, along with distinct changes in brain wave patterns: reduced theta and low gamma power, increased delta, medium gamma, and high gamma power, and altered functional connectivity. Head twitch responses were most frequent at the lowest dose. Endogenous DMT was detected in the cortex of most animals at baseline, suggesting it may be naturally present. The work provides a detailed neurochemical and neurophysiological profile of DMT action in rats.
Physiology
May 1, 2024
Rachel Summerfield, Trent Groenhout, Tiecheng Liu et al.
Intravenous DMT, a psychedelic, increases wakefulness and reduces slow-wave sleep in rats during the first three hours after administration, with a delay in the onset of rapid eye movement sleep. Low (3.75 mg/kg) and high (7.5 mg/kg) doses both produced these effects, while time spent in REM sleep during the light period was unaffected. The findings align with previous reports on serotonergic psychedelics and wakefulness.
bioRxiv (Cold Spring Harbor Laboratory)
August 28, 2023
Nicholas Kolbman, Tiecheng Liu, Peter R. Guzzo et al.
preprint
A single intravenous dose of psilocybin (1 mg/kg or 10 mg/kg) reduced mechanical hypersensitivity in rats for 28 days after formalin-induced chronic pain, but had only a limited effect on thermal hyperalgesia. Formalin injection caused thermal hyperalgesia and bilateral mechanical hypersensitivity in all rats. Psilocybin significantly attenuated the mechanical hypersensitivity throughout the 28-day testing period, while thermal hyperalgesia was reduced only on days 1, 3, 5, and 21. These results suggest psilocybin may have potential for treating chronic pain, though its effects on different pain types vary.