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Čestmír Vejmola

16 papers in the library · 105 citations · publishing 2018-2026

Papers

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Metabolic profile of 25E-NBOH in human liver microsomes, rat urine, and fungus Cunninghamella elegans.

Journal of Pharmaceutical and Biomedical Analysis August 1, 2026 Magdaléna Vágnerová, Petr Palivec, Monika Mrňavá et al.

N-benzylphenethylamines are a class of new psychoactive substances (NPS) that are increasingly being used as recreational drugs with a wide range of adverse effects, possibly even death. Currently, the appearance of new N-benzylphenethylamines far outweighs the studies of their metabolism. One of such compounds, 25E-NBOH, has been on the market for the last seven years but its pharmacological...

EEG microstate dynamics during psilocybin intoxication relate to acute experience and persisting psychological changes

bioRxiv (Cold Spring Harbor Laboratory) June 12, 2026 Nikola Jajcay, Čestmír Vejmola, Jakub Korčák et al.

Abstract Psilocybin and other serotonergic psychedelics show therapeutic promise for psychiatric disorders, yet objective neural correlates linking the acute psychedelic state to persisting psychological outcomes remain limited. Electroencephalography (EEG) microstate analysis characterizes the rapid spatiotemporal organization of large-scale brain activity, offering a millisecond-resolution...

Effects of THC, CBD, and Their Combination on EEG Dynamics in Rats.

Physiological research May 12, 2026 Marcel Bochin, Čestmír Vejmola, Vlastimil Koudelka et al.

Cannabinoids modulate brain network activity, yet the spatial organization and temporal evolution of their electrophysiological effects remain insufficiently characterized in animal models. Here, we investigated how acute oral administration of ?9-tetrahydrocannabinol (THC; 10 mg/kg), cannabidiol (CBD; 10 mg/kg), and their combination influences resting-state EEG dynamics in freely moving rats....

Serotonergic modulation of cortical gamma synchronization: right-lateralized psilocin effects on 40 Hz auditory steady-state responses in rats.

Journal of Neurophysiology April 1, 2026 Inga Griškova-bulanova, Čestmír Vejmola, Tomáš Páleníček

Auditory steady-state responses (ASSRs), particularly at 40 Hz, are promising biomarkers for psychiatric disorders involving dysregulated neural synchronization. Although most ASSR studies have focused on the glutamatergic system, the serotonergic system, specifically 5-HT2A receptor signaling, has received limited attention. Psilocin, the active metabolite of psilocybin and a known 5-HT2A...

Cross-Species Evidence for Psilocin-Induced Visual Distortions: Apparent Motion Is Perceived by Both Humans and Rats.

Biological Psychiatry Global Open Science September 1, 2025 Čestmír Vejmola, Klára Šíchová, Kateřina Syrová et al. 4 citations

Psychedelics, particularly psilocin, are increasingly being studied for their mind-altering effects and potential therapeutic applications in psychiatry. Visual hallucinations, especially the illusion of motion in static images, are a hallmark of their action. Despite growing interest, the underlying mechanisms remain poorly understood, as their systematic evaluation in both humans and animals...

Hexahydrocannabinol: pharmacokinetics, systemic toxicity, and acute behavioral effects in Wistar rats.

The International Journal of Neuropsychopharmacology August 1, 2025 Klára Šíchová, Barbara Mallarino, Lucie Janeckova et al. 1 citation

Hexahydrocannabinol (HHC) is a new psychoactive substance known for its mind-altering effects and temporary legal status. It is widely used in parts of the Europe and United Kingdom as a legal alternative to ∆9-tetrahydrocannabinol, yet little research has explored its effects and safety. This study examined how HHC is processed in the body, its toxicity, and its impact on behavior in male...

The phenomenology of psilocybin's experience mediates subsequent persistent psychological effects independently of sex, previous experience, or setting.

Pharmacological reports : PR June 16, 2025 Tereza Klučková, Marek Nikolič, Filip Tylš et al. 4 citations

Recent studies intensively explore psilocybin's antidepressant potential, but variables like previous experience, repeated use, setting, and sex remain underexplored. This study examines acute and long-term effects of psilocybin in healthy individuals. A double-blind, placebo-controlled, cross-over study included 40 healthy participants (20 females, mean age 38). Each received two doses of...

Hexahydrocannabinol (HHC): pharmacokinetics, systemic toxicity, and acute behavioural effects in Wistar rats.

October 2, 2024 Klára Šíchová, Barbara Mallarino, Lucie Janeckova et al.

Background and purpose: Hexahydrocannabinol (HHC) is a novel psychoactive substance that has gained attention due to its psychotropic effects and temporary legal status. It is widely abused in several EU and US countries, where it serves as a legal and easily accessible alternative to ∆ 9 -tetrahydrocannabinol (∆ 9 -THC). Despite its widespread use, few studies have examined its in vivo effects...

DOES THE PHENOMENOLOGY OF THE PSILOCYBIN EXPERIENCE PREDICT LONG-TERM EFFECTS ON MOOD AND WELL-BEING IN HEALTHY VOLUNTEERS?

IBRO Neuroscience Reports November 6, 2023 Tomáš Páleníček, Tereza Klučková, Marek Nikolič et al.

INTRODUCTION: The mechanisms by which the psychedelic drug psilocybin, a novel rapid-acting antidepressant, improves depressive symptoms are still unclear. One candidate mechanism is the impact of the phenomenology of the psychedelic experience, with positive phenomenology hypothesised to be associated with positive long-term outcomes and fearful phenomenology hypothesised to be associated with...

CROSS-SPECIES EVIDENCE FOR PSILOCIN-INDUCED VISUAL HALLUCINATIONS: RATS PERCEIVE QUALITATIVELY SIMILAR CHANGES AS HUMANS

IBRO Neuroscience Reports October 1, 2023 Čestmír Vejmola, Kateřina Syrová, Klára Šíchová et al.

GABAB receptors are the metabotropic GABA neurotransmitter receptors in the central nervous system constituting a fundamental part of the inhibitory modulation mechanism.These receptors are heterodimers composed of GABAB1 and GABAB2 which function is modulated by the potassium channel tetramerization domain proteins (KCTD) from clade F (KCTD16; KCTD12 and KCTD8).In our experiments we explored...

Underlying pharmacological mechanisms of psilocin-induced broadband desynchronization and disconnection of EEG in rats

Frontiers in Neuroscience June 22, 2023 Filip Tylš, Čestmír Vejmola, Vlastimil Koudelka et al. 9 citations

Introduction Psilocybin is one of the most extensively studied psychedelic drugs with a broad therapeutic potential. Despite the fact that its psychoactivity is mainly attributed to the agonism at 5-HT 2A receptors, it has high binding affinity also to 5-HT 2C and 5-HT 1A receptors and indirectly modulates the dopaminergic system. Psilocybin and its active metabolite psilocin, as well as other...

Acute pharmacological profile of 2C-B-Fly-NBOMe in male Wistar rats-pharmacokinetics, effects on behaviour and thermoregulation.

Frontiers in Pharmacology 2023 Kateřina Syrová, Klára Šíchová, Hynek Danda et al. 4 citations

Introduction: N-2-methoxy-benzylated ("NBOMe") analogues of phenethylamine are a group of new psychoactive substances (NPS) with reported strong psychedelic effects in sub-milligram doses linked to a number of severe intoxications, including fatal ones. In our present work, we provide a detailed investigation of pharmacokinetics and acute behavioural effects of 2C-B-Fly-NBOMe...

Pharmacokinetics, systemic toxicity, thermoregulation and acute behavioural effects of 25CN‐NBOMe

Addiction Biology August 4, 2022 Klára Šíchová, Kateřina Syrová, Edita Kofroňová et al. 8 citations

agonists containing substances emerging on the illicit drug market as a replacement for N,N-diethyllysergamide (LSD). Despite the increasing use of NBOMes for diagnostic, research and recreational purposes, only a limited number of studies have focussed on their in vivo effect. Here, we investigated pharmacokinetics, systemic toxicity, thermoregulation in individually and group-housed animals,...

Psilocin, LSD, mescaline, and DOB all induce broadband desynchronization of EEG and disconnection in rats with robust translational validity

Translational Psychiatry October 2, 2021 Čestmír Vejmola, Filip Tylš, Václava Piorecká et al. 41 citations

Abstract Serotonergic psychedelics are recently gaining a lot of attention as a potential treatment of several neuropsychiatric disorders. Broadband desynchronization of EEG activity and disconnection in humans have been repeatedly shown; however, translational data from animals are completely lacking. Therefore, the main aim of our study was to assess the effects of tryptamine and...

Psychedelic therapy in the Czech Republic: A theoretical concept or a realistic goal?

Journal of Psychedelic Studies February 21, 2019 Zuzana Postránecká, Čestmír Vejmola, Filip Tylš 6 citations

Psychedelic research has been associated with the Czech Republic since the early 19th century and, after a long period of involuntary dormancy, it has recently gained new opportunities to follow up on its roots and evolve. This article briefly describes the history of psychedelic research in the Czech Republic, summarizes the role of the UN Drug Conventions, and discusses the Czech and...

Mephedrone (4-Methylmethcathinone): Acute Behavioral Effects, Hyperthermic, and Pharmacokinetic Profile in Rats

Frontiers in Psychiatry January 10, 2018 Klára Šíchová, Nikola Pinterová, Monika Židková et al. 28 citations

Mephedrone (MEPH) is a synthetic cathinone derivative with effects that mimic MDMA and/or cocaine. Our study in male Wistar rats provides detailed investigations of MEPH's and its primary metabolite nor-mephedrone's (nor-MEPH) pharmacokinetics and bio-distribution to four different substrates (serum, brain, lungs, and liver), as well as comparative analysis of their effects on locomotion [open...