PSILOCYBIN – summary of knowledge and new perspectives

European neuropsychopharmacology: the journal of the European College of Neuropsychopharmacology (Impact Factor: 4.37). 01/2013; 24(3). DOI: 10.1016/j.euroneuro.2013.12.006


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 and recent knowledge on psilocybin. It briefly deals with its history, discusses the pharmacokinetics and pharmacodynamics, and compares its action in humans and animals. It attempts to describe the mechanism of psychedelic effects and objectify its action using modern imaging and psychometric methods. Finally, it describes its therapeutic and abuse potential.

Download full-text


Available from: Filip Tylš, Jul 21, 2014
619 Reads
  • Source
    • "This supports the idea that psilocin also had amnestic effects. It is well known from the literature that psilocin effects are mainly mediated through 5-HT 2A/C and 5-HT 1A receptors (Tyls et al., 2013). These receptors are widely distributed in the neocortex , basal ganglia, limbic system, and hippocampus and in the case of 5-HT 1A also in rapheal nuclei (Barnes and Sharp, 1999). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The involvement of the serotonin system in the pathophysiology of schizophrenia has been elucidated by experiments with hallucinogens. Application of a hallucinogen to humans leads to changes in perception, cognition, emotions, and induction of psychotic-like symptoms that resemble symptoms of schizophrenia. In rodent studies, their acute administration affects sensorimotor gating, locomotor activity, social behavior, and cognition including working memory, the phenotypes are considered as an animal model of schizophrenia. The complexity and singularity of human cognition raises questions about the validity of animal models utilizing agonists of 5-HT2A receptors. The present study thus investigated the effect of psilocin on memory acquisition, reinforced retrieval, and memory consolidation in rats. Psilocin is a main metabolite of psilocybin acting as an agonist at 5-HT2A receptors with a contribution of 5-HT2C and 5-HT1A receptors. First, we tested the effect of psilocin on the acquisition of a Carousel maze, a spatial task requiring navigation using distal cues, attention, and cognitive coordination. Psilocin significantly impaired the acquisition of the Carousel maze at both doses (1 and 4 mg/kg). The higher dose of psilocin blocked the learning processes even in an additional session when the rats received only saline. Next, we examined the effect of psilocin on reinforced retrieval and consolidation in the Morris water maze (MWM). The dose of 4 mg/kg disrupted reinforced retrieval in the MWM. However, the application of a lower dose was without any significant effect. Finally, neither the low nor high dose of psilocin injected post-training caused a deficit in memory consolidation in the MWM. Taken together, the psilocin dose dependently impaired the acquisition of the Carousel maze and reinforced retrieval in MWM; however, it had no effect on memory consolidation.
    Frontiers in Behavioral Neuroscience 05/2014; 8:180. DOI:10.3389/fnbeh.2014.00180 · 3.27 Impact Factor