Frontiers in Human Neuroscience
March 18, 2021
Emma R. Huels, Hyoungkyu Kim, UnCheol Lee et al.
51 citations
Shamanic practitioners in trance show brain changes that overlap with but are distinct from those caused by psychedelic drugs. In 24 practitioners and 24 controls, EEG recordings during shamanic drumming revealed increased gamma power linked to visual changes, decreased low alpha and increased low beta connectivity, reduced gamma-band signal diversity tied to insightfulness, and increased criticality in beta and gamma bands correlating with complex imagery. Practitioners' altered-state scores matched or exceeded those of people on psychedelics. The findings indicate that shamanic trance and psychedelic states share some phenomenal features but produce unique neural signatures.
bioRxiv : the preprint server for biology
February 15, 2025
Nicolas G. Glynos, Emma R. Huels, Amanda Nelson et al.
11 citations
preprint
Intravenous DMT in rats caused dose-dependent increases in serotonin and dopamine in the medial prefrontal and somatosensory cortices, along with changes in brain wave patterns: reduced theta and low gamma power, increased delta, medium gamma, and high gamma power, and altered functional connectivity. All doses produced head twitch responses, most after the low dose. For the first time, endogenous DMT was measured in these cortical sites at levels comparable to serotonin and dopamine, suggesting a physiological role for the compound. The findings point to shared mechanisms with other psychedelics and support DMT's potential for treating psychiatric disorders.
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)
October 14, 2025
Nicholas Kolbman, Amanda Nelson, Rachel Summerfield et al.
1 citation
preprint
Psilocybin and DMT, two serotonergic psychedelics, delay the onset of slow-wave sleep and REM sleep, and cause a short-lasting increase in wakefulness and decrease in slow-wave sleep in rats. Psilocybin also reduces REM sleep, decreases theta power and coherence, and increases high gamma power and coherence during wake and slow-wave sleep, as well as increasing high gamma coherence during REM sleep. DMT increases gamma coherence only during wakefulness. The enhanced high gamma functional connectivity suggests that psychedelic-induced changes in neural dynamics can occur independently of arousal states.
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.
Frontiers in Psychology
January 1, 2025
Emma R. Huels, Lily Carter, Gang Xu et al.
Shamanic journeying, an ancient spiritual practice, produces dynamic changes in heart function measurable through heart rate variability (HRV). In a single subject, drumming initiation decreased heart rate and increased HRV measures, while shapeshifting increased heart rate and certain HRV indicators. Qigong meditation also increased HRV measures, with greater changes in some metrics than drumming initiation. These findings suggest shamanic journeying involves widespread cardiac and physiological changes that can be tracked visually and via ultra-short-term HRV.