Nature Communications
August 3, 2026
Frederik Gudmundsen, Julia Czurylo, Daniel Ryskamp Rijsketic et al.
Serotonergic psychedelics show therapeutic potential across neuropsychiatric disorders despite transient acute effects. These compounds share serotonin 2 A receptor agonism but differ in broader pharmacology, motivating a systematic comparison of their neurobiological effects. Here, we use [18 F]FDG-PET in rats to assess acute and one-week effects of psilocybin, LSD, and 2C-B on brain metabolic...
PsyArXiv
May 24, 2026
Naja Bralic, Elena Bragagnolo, Mikael Palner
preprint
Background and objective: Anxiety disorders are among the most prevalent psychiatric disorders worldwide and affect all age groups. Current pharmacological treatments, such as selective serotonergic reuptake inhibitors (SSRI’s) and benzodiazepines, have limitations in terms of adverse effects and efficacy, which highlights the need for alternative therapies. Serotonergic psychedelics have...
PsyArXiv
May 14, 2026
Jacob Cohen, Peter Parbo, Per Trads Ørskov et al.
preprint
Low doses of psilocybin as adjunct pharmacological treatment to virtual reality exposure therapy for social anxiety disorder: A study protocol for a double-blind randomized controlled trial.
Open Access CRIS of the University of Bern
February 9, 2026
Mikael Palner, Elisabeth Kolesnik, Christina Baun et al.
Mammalian brain may contain an endogenous pool of the psychedelic substance N,N-dimethyltryptamine (DMT), which may act as a co-transmitter with serotonin (5-HT). We tested the joint hypotheses. We tested the joint hypotheses that endogenous DMT would accumulate in rat brain after inhibiting monoamine oxidase with pargyline, whereas its acidic metabolite 3-indoleacetic acid (3-IAA) would...
Neuropharmacology
February 9, 2026
Mikael Palner, Elisabeth Kolesnik, Christina Baun et al.
Mammalian brain may contain an endogenous pool of the psychedelic substance N,N-dimethyltryptamine (DMT), which may act as a co-transmitter with serotonin (5-HT). We tested the joint hypotheses. We tested the joint hypotheses that endogenous DMT would accumulate in rat brain after inhibiting monoamine oxidase with pargyline, whereas its acidic metabolite 3-indoleacetic acid (3-IAA) would...
Psychedelic Medicine
February 3, 2026
Anton T. Gregersen, Tobias P. Whelan, Caroline T. Golden et al.
2 citations
Introduction: Cognitive flexibility is essential for behavioral adaptation in response to environmental changes and is impaired in various neuropsychiatric disorders. The serotonergic psychedelic psilocybin has shown potential in enhancing cognitive flexibility, although with mixed results. In this study, we investigated the effects of psilocybin on cognitive flexibility in rats using a...
Frontiers in Psychiatry
2026
Sivert Drange, Jacob Cohen, Sys Stybe Johansen et al.
1 citation
Obsessive-Compulsive Disorder (OCD) can present significant challenges to individuals mental health, characterized by intrusive thoughts and repetitive maladaptive behaviors. Recent research into alternative treatments has highlighted psychedelics, notably psilocybin, for their potential therapeutic benefits in various psychiatric disorders, including OCD. This case study evaluated the impact...
February 27, 2025
Anton T. Gregersen, Tobias P. Whelan, Caroline T. Golden et al.
preprint
IntroductionCognitive flexibility is essential for adapting behavior in response to environmental changes and is implicated in various neuropsychiatric disorders. Psilocybin, a serotonergic psychedelic, has shown potential in enhancing cognitive flexibility, though results are mixed. This study investigates the effects of psilocybin on cognitive flexibility using a three-choice visual reversal...
December 30, 2024
Sivert Drange, Jacob Cohen, Sys Stybe Johansen et al.
1 citation
preprint
Background: Obsessive-Compulsive Disorder (OCD) presents significant challenges to individuals mental health, characterized by intrusive thoughts and repetitive maladaptive behaviours. Recent exploration into alternative treatments has spotlighted psychedelics, notably psilocybin, for their potential therapeutic benefits in different psychiatric disorders, including OCD. This case study delves...
May 28, 2024
Frederik Gudmundsen, Julia Czurylo, Camilla Trang Vo et al.
1 citation
preprint
Serotonergic psychedelic drugs have shown promising benefits in trials for various neuropsychiatric disorders. While the acute effects of these psychedelics last only a few hours, the positive therapeutic effects can persist long after a single administration. Serotonergic psychedelics produce their psychedelic effects by activating serotonin 2A receptors, but they differ in other...
The Journal of neuroscience : the official journal of the Society for Neuroscience
November 8, 2023
Lindsay P. Cameron, Joseph Benetatos, Vern Lewis et al.
88 citations
Serotonergic psychedelics, such as psilocybin and LSD, have garnered significant attention in recent years for their potential therapeutic effects and unique mechanisms of action. These compounds exert their primary effects through activating serotonin 5-HT2A receptors, found predominantly in cortical regions. By interacting with these receptors, serotonergic psychedelics induce alterations in...
Molecular Psychiatry
September 1, 2023
Kat F. Kiilerich, Joe Lorenz, Malthe B. Scharff et al.
48 citations
Psilocybin (a classic serotonergic psychedelic drug) has received appraisal for use in psychedelic-assisted therapy of several psychiatric disorders. A less explored topic concerns the use of repeated low doses of psychedelics, at a dose that is well below the psychedelic dose used in psychedelic-assisted therapy and often referred to as microdosing. Psilocybin microdose users frequently report...
January 4, 2023
Klemens Egger, Frederik Gudmundsen, Naja Støckel Jessen et al.
preprint
RationaleThe psychedelic effects of the traditional Amazonian botanical decoction known as ayahuasca are attributed to the effects of N,N-dimethyltryptamine (DMT) at brain serotonin 5-HT2A receptors. To make oral DMT bioavailable, ayahuasca additionally contains reversible monoamine oxidase A (MAO-A) inhibitors, namely β-carboline alkaloids such as harmine. However, there is lacking biochemical...
Frontiers in Pharmacology
2023
Klemens Egger, Frederik Gudmundsen, Naja Støckel Jessen et al.
17 citations
Rationale: The psychedelic effects of the traditional Amazonian botanical decoction known as ayahuasca are often attributed to agonism at brain serotonin 5-HT2A receptors by N,N-dimethyltryptamine (DMT). To reduce first pass metabolism of oral DMT, ayahuasca preparations additionally contain reversible monoamine oxidase A (MAO-A) inhibitors, namely β-carboline alkaloids such as harmine....
Molecules
April 22, 2021
Paul Cumming, Milan Scheidegger, Dario Dornbierer et al.
45 citations
Hallucinogens are a loosely defined group of compounds including LSD, N,N-dimethyltryptamines, mescaline, psilocybin/psilocin, and 2,5-dimethoxy-4-methamphetamine (DOM), which can evoke intense visual and emotional experiences. We are witnessing a renaissance of research interest in hallucinogens, driven by increasing awareness of their psychotherapeutic potential. As such, we now present a...
Biochemical Pharmacology
April 13, 2020
A. Jensen, Adam L. Halberstadt, Emil Märcher-Rørsted et al.
25 citations
The remarkable effects exhibited by classical psychedelics in recent clinical trials have spawned considerable interest in 5-HT2A receptor (5-HT2AR) activation as a treatment strategy for several psychiatric/cognitive disorders. In this study we have continued our development of 25CN-NBOH, one of the most 5-HT2AR-selective agonists reported to date, as a pharmacological tool for exploration of...
bioRxiv Preprint Server
February 23, 2020
X. Zhao, K. T. Meyers, A. Mcbride et al.
1 citation
preprint
Serotonin 2A receptors (5-HT2ARs) mediate the effects of hallucinogenic drugs and antipsychotic medications, and are reduced in schizophrenia patients’ brains. However, the mechanisms that regulate 5-HT2AR expression remain poorly understood. We show that an environmental stimulus, sleep deprivation, upregulates 5-HT2ARs in the mouse frontal cortex (FC) in just 6-8 hours. This induction...
Journal of Nuclear Medicine
October 18, 2010
Anders Ettrup, Mikael Palner, Nic Gillings et al.
50 citations
UNLABELLED: PET brain imaging of the serotonin 2A (5-hydroxytryptamine 2A, or 5-HT(2A)) receptor has been widely used in clinical studies, and currently, several well-validated radiolabeled antagonist tracers are used for in vivo imaging of the cerebral 5-HT(2A) receptor. Access to 5-HT(2A) receptor agonist PET tracers would, however, enable imaging of the active, high-affinity state of...