BACKGROUND: 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 is challenging. METHODS: To investigate psilocin-induced visual distortions, we designed a 2-choice visual discrimination task. Human participants and male rats indicated whether an image appeared static or moving while the image either actually moved or did not. In humans, performance was compared with self-reported hallucination intensity, Altered States of Consciousness scale scores, and psilocin plasma levels. Rats were tested in 2 distinct tasks, a luminance-based task and a motion-based task. Their performance was evaluated alongside decision time. RESULTS: Both species exhibited significant impairment in distinguishing static from dynamic visual stimuli while under psilocin's influence. In humans, this impairment followed the time course of psilocin plasma levels and hallucination intensity. In rats, psilocin selectively impaired performance in the motion-based task, while performance in the luminance-based task remained intact, indicating a specific effect on visual perception. Decision time was linked to discrimination impairment. CONCLUSIONS: Psilocin impaired static-dynamic discrimination in both species, providing the first evidence that rats experience visual distortions similar to those reported by humans. The correlations between discrimination impairment, psilocin levels, and hallucination intensity in humans reinforce psilocin's effects on visual perception. This approach provides a valuable tool for investigating the neurobiology of altered visual perception in drug-induced states and psychiatric conditions.

In this study, we explored how psilocin, a compound derived from psilocybin in magic mushrooms, alters visual perception in humans and rats. Using a visual discrimination task, both species were tested on their ability to distinguish static from dynamic images. Psilocin caused humans to misclassify static images as dynamic and induced similar visual distortions in rats. This is the first study to demonstrate that rats experience psilocin-induced visual distortions comparable to those reported by humans, thereby providing a valuable foundation for further research on visual alterations across species.

• Keywords
• Human, Psilocin, Psychedelics, Rat, Vision, Visual hallucinations,
• Publication type
• Journal Article MeSH

Mushroom poisoning has always been a threat to human health. There are a large number of reports about ingestion of poisonous mushrooms every year around the world. It attracts the attention of researchers, especially in the aspects of toxin composition, toxic mechanism and toxin application in poisonous mushroom. Inocybe is a large genus of mushrooms and contains toxic substances including muscarine, psilocybin, psilocin, aeruginascin, lectins and baeocystin. In order to prevent and remedy mushroom poisoning, it is significant to clarify the toxic effects and mechanisms of these bioactive substances. In this review article, we summarize the chemistry, most known toxic effects and mechanisms of major toxic substances in Inocybe mushrooms, especially muscarine, psilocybin and psilocin. Their available toxicity data (different species, different administration routes) published formerly are also summarized. In addition, the treatment and medical application of these toxic substances in Inocybe mushrooms are also discussed. We hope that this review will help understanding of the chemistry and toxicology of Inocybe mushrooms as well as the potential clinical application of its bioactive substances to benefit human beings.

• Keywords
• Inocybe mushroom, muscarine, psilocin, psilocybin, toxicology,
• MeSH
• Agaricales chemistry   metabolism   physiology   MeSH
• Lectins chemistry   pharmacology   MeSH
• Humans MeSH
• Muscarine chemistry   poisoning   toxicity   MeSH
• Organophosphorus Compounds chemistry   toxicity   MeSH
• Mushroom Poisoning etiology   therapy   MeSH
• Psilocybin analogs & derivatives   chemistry   poisoning   toxicity   MeSH
• Tryptamines chemistry   toxicity   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Lectins MeSH
• Muscarine MeSH
• N, N, N-trimethyl-4-phosphoryloxytryptamine MeSH Browser
• Organophosphorus Compounds MeSH
• psilocin MeSH Browser
• Psilocybin MeSH
• Tryptamines MeSH

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-HT2A receptors in information processing is less clear. OBJECTIVES: We studied ERPs in a serotonergic model of psychosis, induced by psilocybin, a psychedelic with 5-HT2A/C agonistic properties, in healthy volunteers. METHODS: Twenty subjects (10M/10F) were given 0.26 mg/kg of psilocybin orally in a placebo-controlled, double-blind, cross-over design. ERPs (P300, MMN) were registered during the peak of intoxication. Correlations between measured electrophysiological variables and psilocin serum levels and neuropsychological effects were also analyzed. RESULTS: Psilocybin induced robust psychedelic effects and psychotic-like symptoms, decreased P300 amplitude (p = 0.009) but did not affect the MMN. Psilocybin's disruptive effect on P300 correlated with the intensity of the psychedelic state, which was dependent on the psilocin serum levels. We also observed a decrease in N100 amplitude (p = 0.039) in the P300 paradigm and a negative correlation between P300 and MMN amplitude (p = 0.014). CONCLUSIONS: Even though pre-attentive cognition (MMN) was not affected, processing at the early perceptual level (N100) and in higher-order cognition (P300) was significantly disrupted by psilocybin. Our results have implications for the role of 5-HT2A receptors in altered information processing in psychosis and schizophrenia.

• Keywords
• ERP, Human, MMN, Model of psychosis, P300, Psilocybin,
• MeSH
• Acoustic Stimulation methods   MeSH
• Adult MeSH
• Double-Blind Method MeSH
• Electroencephalography drug effects   methods   MeSH
• Hallucinogens pharmacology   MeSH
• Cross-Over Studies MeSH
• Cognition drug effects   physiology   MeSH
• Event-Related Potentials, P300 drug effects   physiology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Attention drug effects   physiology   MeSH
• Psilocybin adverse effects   pharmacology   MeSH
• Aged MeSH
• Healthy Volunteers MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Controlled Clinical Trial MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Hallucinogens MeSH
• Psilocybin MeSH

• Keywords
• animal models, clinical studies, cognition, neuropsychiatric disorders, preclinical studies,
• Publication type
• Journal Article MeSH