Acute effects of subanesthetic ketamine on cerebrovascular hemodynamics in humans: A TD-fNIRS neuroimaging study
Adelaida Castillo, Julien Dubois, Ryan M. Field, Frank A. Fishburn, Andrew Gundran, Wilson C. Ho, Sami Jawhar, Julian Kates-Harbeck, Zahra M. Aghajan, Naomi Miller, Katherine L. Perdue, Jake Phillips, Wesley C Ryan, Mahdi Shafiei, Felix Scholkmann, Moriah Taylor
bioRxiv (Cold Spring Harbor Laboratory) January 9, 2023 preprint DOI: 10.1101/2023.01.06.522912 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Single-blind, placebo-controlled study with a non-randomized design |
|---|---|
| Sample size | 15 |
| Population | Healthy participants (8 females, 7 males, age 32.4 ± 7.5 years) |
| Interventions | Ketamine Placebo (saline) |
| Dose | 0.75 mg/kg |
| Topics | Esketamine Ketamine |
| Citations | 3 |
| Key points | Ketamine administration caused an altered state of consciousness and systemic physiological changes, including increased pulse rate and electrodermal activity. It led to a brain-wide reduction in the fractional amplitude of low-frequency fluctuations and decreased global brain connectivity in the prefrontal region. The authors provide preliminary evidence that neural and physiological metrics together may predict subjective mystical experiences and reductions in depressive symptomatology. |
Abstract
Abstract Quantifying neural activity in natural conditions (i.e. conditions comparable to the standard clinical patient experience) during the administration of psychedelics may further our scientific understanding of the effects and mechanisms of action. This data may facilitate the discovery of novel biomarkers enabling more personalized treatments and improved patient outcomes. In this single-blind, placebo-controlled study with a non-randomized design, we use time-domain functional near-infrared spectroscopy (TD-fNIRS) to measure acute brain dynamics after intramuscular subanesthetic ketamine (0.75 mg/kg) and placebo (saline) administration in healthy participants ( n = 15, 8 females, 7 males, age 32.4 ± 7.5 years) in a clinical setting. We found that the ketamine administration caused an altered state of consciousness and changes in systemic physiology (e.g. increase in pulse rate and electrodermal activity). Furthermore, ketamine led to a brain-wide reduction in the fractional amplitude of low frequency fluctuations (fALFF), and a decrease in the global brain connectivity of the prefrontal region. Lastly, we provide preliminary evidence that a combination of neural and physiological metrics may serve as predictors of subjective mystical experiences and reductions in depressive symptomatology. Overall, our studies demonstrated the successful application of fNIRS neuroimaging to study the physiological effects of the psychoactive substance ketamine and can be regarded as an important step toward larger scale clinical fNIRS studies that can quantify the impact of psychedelics on the brain in standard clinical settings.
Comparable studies
Other non-randomized and open-label trials on ketamine, most cited first.
Citations in the library
Cites 29
- Measurement of dissociative states with the Clinician‐Administered Dissociative States Scale (CADSS) Journal of Traumatic Stress 1998
- Quality of Acute Psychedelic Experience Predicts Therapeutic Efficacy of Psilocybin for Treatment-Resistant Depression Frontiers in Pharmacology January 17, 2018
- Psychedelics and the essential importance of context. Journal of Psychopharmacology February 15, 2018
- The Standardized Psychometric Assessment of Altered States of Consciousness (ASCs) in Humans Pharmacopsychiatry July 1, 1998
- Factor Analysis of the Mystical Experience Questionnaire: A Study of Experiences Occasioned by the Hallucinogen Psilocybin Journal for the Scientific Study of Religion December 1, 2012
and 24 more in the library