Filip Tylš

• MD PhD
• Researcher at National Institute of Mental Health

Background 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. Methods A double-blind, placebo-controlled, cross-over study included 40 healthy part...

Background Recent studies have intensively explored the potential antidepressant effects of psilocybin. However, important variables such as previous experience, repeated administration, setting and sex remain underexplored. This study describes the acute psilocybin experience and long-term effects in a small sample of healthy individuals. Methods...

The use of psychedelics for various purposes was common in different civilizations throughout human history and has been explored scientifically for more than a century. Although the applications of psychedelics show promise in the treatment of various psychiatric and neurological indications, as well as in facilitation of well-being and personal g...

The growing interest in and prevalence of the use of psychedelics, as well as the potential benefits and negative consequences associated with psychedelic experiences, create a need for mental health specialists to be able to provide adequate and effective intervention regarding the content and consequences of these experiences, that is, psychedeli...

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-HT2A receptors, it has high binding affinity also to 5-HT2C and 5-HT1A receptors and indirectly modulates the dopaminergic system. Psilocybin and its a...

Psilocybin is investigated as a fast-acting antidepressant used in conjunction with psychotherapy. Intact cognitive functions, including memory, are one of the basic conditions of effective psychedelic-assisted therapy. While cognitive and memory processing is attenuated on various domains during psilocybin intoxication, the effect of psilocybin on...

In this paper we present an exploratory study on the understanding of reality among scientists. The nature of reality has been a conundrum for generations of theologians, philosophers and scientists as well as the lay public. It also appears as a scientific problem in various disciplines, from physics to psychiatry and neuroscience. For the purpose...

Objectivity is an essential concept with a convoluted history in both philosophy and science. Th is book presents a theoretical analysis and contemporary revision of the concept with the help of experimental philosophy. In recent years, experimental philosophy has substantially enriched philosophy by adopting methods from sociology, psychology and...

Psilocybin is a classical serotoninergic psychedelic that induces cognitive disruptions similar to psychosis. Gamma activity is affected in psychosis and is tightly related to cognitive processing. The 40 Hz auditory steady-state responses (ASSR) are frequently used as indicators to test the ability to generate gamma activity. Based on previous lit...

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...

Serotonergic agonist psilocybin is a psychedelic with antidepressant potential. Sleep may interact with psilocybin’s antidepressant properties like other antidepressant drugs via induction of neuroplasticity. The main aim of the study was to evaluate the effect of psilocybin on sleep architecture on the night after psilocybin administration. Regard...

All known psychedelics are 5-HT2A receptor agonists and induce extensive psychological changes. Abnormal function of serotonergic transmission is seen today as one of the etiopathogenetic factors of schizophrenia. Therefore, psychedelics are used to model this disease. The representatives of two main classes – tryptamines (psilocin, LSD) and phenet...

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 Co...

Measurements of brain electrical activity in animals are essential for the validation of the pharmaco-effect of drugs. The way to evaluate these recordings should be comparable to that of EEG in humans. Methods that visualize the results of the measured EEG recording include brain mapping in two-dimensional or three-dimensional space. The most comm...

Objectives: Although schizencephaly belongs to the class of neurodevelopmental disorders, which are a well-known predisposing factor for psychosis, there is a lack of relevant studies and diagnostic guidelines on this relationship. Method: A case report of first-episode psychosis with persistent negative symptoms associated with schizencephaly i...

Objective Time-course of ketamine effect was assessed in depressive patients by QEEG to elucidate changes associated with treatment and to assess potential predictors of response. Methods The analysis was completed from data of two double-blind, cross-over, placebo-controlled studies, assessing the effect of ketamine infusion (0.54 mg/kg) in 51 in...

Electroencephalography (EEG) is a method that reflects the electrical activity of the brain. Changes in electrical activity can be reflected also in 2D or 3D maps Measurements of brain electrical activity in animals are essential for the validation of the pharmaco-effect on the brain. The translational approach using similar methods for quantitativ...

Rationale: Disruption of auditory event-related evoked potentials (ERPs) P300 and mismatch negativity (MMN), electrophysiological markers of attentive and pre-attentive cognitive processing, is repeatedly described in psychosis and schizophrenia. Similar findings were observed in a glutamatergic model of psychosis, but the role of serotonergic 5-H...

Metabolic and behavioural effects of, and interactions between Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are influenced by dose and administration route. Therefore we investigated, in Wistar rats, effects of pulmonary, oral and subcutaneous (sc.) THC, CBD and THC+CBD. Concentrations of THC, its metabolites 11-OH-THC and THC-COOH, and CBD...

Rationale: Self-report studies indicate that cannabis could increase sexual desire in some users. We hypothesized that intoxication increases activation of brain areas responsive to visual erotica, which could be useful in the treatment of hypoactive sexual desire disorder, a condition marked by a lack of sexual desire. Objectives: The aim of th...

Research on psychedelics and of their clinical utilization has been evolving separately from placebo research. There are several parallels between this two research fields with possible mutual enrichment. Substantial role of extrapharmacological variables in psychedelic interventions has implications for next research and for potential regulation o...

OBJECTIVES The serotonergic hallucinogen psilocybin, has profound effects on the human mind, which can be characterized by alteration in perception, thinking disorder and strong emotional salience. The character of the altered state of consciousness induced by hallucinogens is hardly predictable; while an important role has the environment in which...

Comparison of human and rat data of quantitative analysis of EEG signal.

This chapter focuses on the potential use of serotonergic hallucinogen psilocybin in clinical as well as experimental psychiatry, addictology, and neurology. It presents the results of recent clinical studies with psilocybin and summarizes the psychological and neurobiological aspects of its effect in specific therapeutic indications. In addition,...

Unconscious processes have long been forgotten in neuroscientific field for their difficult objectification. Gradually, they have become a subject of investigation in cognitive neuroscience, that uncovers their importance in decision-making and behavior. However, cognitive neuroscience research has difficulties to take into account the dynamics of...

Psilocybin has recently attracted a great deal of attention as a clinical research and therapeutic tool. The aim of this paper is to bridge two major knowledge gaps regarding its behavioural pharmacology - sex differences and the underlying receptor mechanisms. We used psilocin (0.25, 1 and 4 mg/kg), an active metabolite of psilocybin, in two behav...

Perinatal immune challenge leads to neurodevelopmental dysfunction, permanent immune dysregulation and abnormal behaviour, which have been shown to have translational validity to findings in human neuropsychiatric disorders (e.g. schizophrenia, mood and anxiety disorders, autism, Parkinson's disease and Alzheimer's disease). The aim of this animal...

The serotonergic hallucinogen psilocybin has received a lot of attention due to its potential use in clinical as well as experimental psychiatry, addictology and neurology. This text presents the results of recent clinical studies with psilocybin in the context of its historical use and summarizes the psychological and biological aspects of its eff...

Pharmacological models of psychosis bring a unique tool for studying brain disconnection in humans as well as in animals. Even though several electrophysiological biomarkers have been already described in schizophrenia, little is known about EEG biomarkers in pharmacological models of psychosis and about the translational validity of these data. St...

In the present study we investigated the potential antipsychotic effects of the mGlu2/3 agonist LY379268 on changes in EEG power spectra and coherence in the ketamine model of psychosis. In order to use behaviorally active drug doses, experiments detecting changes in locomotor activity and sensorimotor gating were also conducted. In EEG experiments...

Cannabis consumption has individual influence to cognitive and psychomotor functions of drivers and it has been generally accepted that driving under influence is risky in the perspective of traffic safety. However, rules how to assess fitness to drive are not quite clear. The psychoactive compound delta-9-tetrahydrocannabinol (THC) impairs cogniti...

Existuje řada důkazů, které potvrzují vliv delta-9-tetrahydrokanabinolu (THC) na indukci pozitivních psychotických symptomů u lidí, na zhoršení symptomů probíhající psychózy, na rozvoji psychózy u chronických adolescentních uživatelů konopí a na generování abnormální funkční konektivity mozku korelující se vznikem psychotických symptomů. Současně e...

Considering the fact that the Czech Republic is a country with one of the highest prevalence of cannabis usage in the world, the relationship of this drug to the development of psychosis becomes important. It becomes a sensitive issue even in our circumstances. Throughout the scientific world the topic of cannabis usage and its link with psychosis...

Naším hlavním cílem bylo prozkoumat v animálním modelu u potkana akutní účinky delta-9-tetrahydrokanabinolu (THC) na lokomoční aktivitu (test otevřeného pole) a senzorimotorické zpracování informací (prepulzní inhibice akustické úlekové reakce, PPI ASR). Smyslem experimentu bylo zjistit, zda-li akutní účinky THC mohou indukovat psychóze podobné cho...

Psilocybin, a psychoactive alkaloid contained in hallucinogenic mushrooms, is nowadays given a lot of attention in the scientific community as a research tool for modeling psychosis as well as due to its potential therapeutic effects. However, it is also a very popular and frequently abused natural hallucinogen. This review summarizes all the past...

Rationale and objectives: Behavioral, neurochemical and pharmaco-EEG profiles of a new synthetic drug 4-bromo-2,5-dimethoxyphenethylamine (2C-B) in rats were examined. Materials and methods: Locomotor effects, prepulse inhibition (PPI) of acoustic startle reaction (ASR), dopamine and its metabolite levels in nucleus accumbens (NAc), EEG power sp...

Schizophrenia has been associated with disrupted neural networks, which can be documented by the changes in EEG. NMDA antagonists as well as 5-HT2 agonists induce psychosis-like symptoms in animals and humans.Objectives Spectral analyses of NMDA antagonists/5-HT2 agonists have been performed by many authors, however no EEG coherence and spectra was...

This study was designed to evaluate the changes in EEG power spectra and EEG coherence in a ketamine model of psychosis in rats. Analyses of behavioral measurements--locomotion and sensorimotor gating--and the pharmacokinetics of ketamine and norketamine were also conducted. Ketamine and norketamine levels in rat sera and brains were analyzed by ga...

Deficits in senzorimotor information processing as well as some changes in quantitative EEG (qEEG) are characteristic for schizophrenia. This study focuses on a comparision of two hallucinogens, tryptamine (psilocin) and phenylethylamine (meskaline), in an animal model of psychosis. The registration of qEEG was performed from 12 subdural electrodes...