Serotonergic modulation of cortical gamma synchronization: right-lateralized psilocin effects on 40 Hz auditory steady-state responses in rats.
Inga Griškova-bulanova, Čestmír Vejmola, Tomáš Páleníček
Journal of Neurophysiology April 1, 2026 DOI: 10.1152/jn.00519.2025 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Preclinical experimental study Peer reviewed |
|---|---|
| Sample size | 8 |
| Population | Adult male Wistar rats |
| Intervention | Psilocin |
| Dose | 4 mg/kg |
| Duration | 30 min after subcutaneous administration |
| Measures | Phase-locking index (PLI), Event-related spectral perturbation (ERSP) |
| Topics | Psilocybin Serotonin |
| Keywords | Auditory steady-state response Gamma oscillations Neural synchrony Rats |
| Key findings | Psilocin selectively decreased phase-locking index at 40 Hz stimulation in the right temporal cortex, with no significant changes in frontal or left temporal regions or at 80 Hz stimulation. |
Abstract
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 receptor agonist, alters cortical oscillatory activity, but its effects on ASSR dynamics remain unclear. In this study, we examined psilocin's effects on ASSRs in eight adult male Wistar rats implanted with 21 cortical electrodes. The rats were exposed to 40 Hz and 80 Hz click-train stimulation before and 30 min after subcutaneous psilocin administration (4 mg/kg). EEG signals were analyzed using time-frequency decomposition to extract phase-locking index (PLI) and event-related spectral perturbation (ERSP) values from frontal and temporal regions of both hemispheres. Psilocin selectively decreased PLI at 40 Hz stimulation in the right temporal cortex, with no significant changes in the frontal or left temporal regions, nor in response to 80 Hz stimulation. ERSP analysis revealed a global reduction in spectral power after psilocin administration in response to 80 Hz stimuli, but no consistent effects at 40 Hz. These results indicate that psilocin induces region- and frequency-specific alterations in auditory neural synchronization, characterized by right-lateralized disruption of 40 Hz phase-locking. This highlights the sensitivity of low-gamma oscillations to serotonergic modulation and supports the use of ASSR paradigms in translational models of altered perceptual and cognitive states.NEW & NOTEWORTHY This is the first preclinical study to demonstrate that psilocin selectively disrupts auditory steady-state responses (ASSRs) in rats in a frequency- and region-specific manner. The findings indicate a right-lateralized reduction in phase-locking at 40 Hz, along with a global suppression of spectral power at 80 Hz. These results provide new insights into the serotonergic modulation of neural synchrony and support the use of ASSRs as a translational biomarker for altered perceptual states.
Comparable studies
Other preclinical and animal studies on serotonin, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Psilocybin induces rapid and persistent growth of dendritic spines in frontal cortex in vivo Mice | 2021 | Observational cohort | |
| Neurotoxicity of the psychedelic amphetamine, methylenedioxymethamphetamine. Rats (implied by typical neurochemical study context) | 1987 | Experimental study | |
| Psychedelics promote neuroplasticity through the activation of intracellular 5-HT2A receptors In vitro and in vivo (rodent) models | 2023 | Experimental study | |
| 3,4-Methylenedioxymethamphetamine and 3,4-methylenedioxyamphetamine destroy serotonin terminals in rat brain: quantification of neurodegeneration by measurement of [3H]paroxetine-labeled serotonin uptake sites. Rat brain | 1987 | Animal experiment | |
| Comparison of the monoamine transporters from human and mouse in their sensitivities to psychostimulant drugs Human and mouse dopamine, norepinephrine, and serotonin transporters expressed in cells | 2006 | In vitro laboratory study |
Citations in the library
Cites 7
- Serotonin 5-HT2A, 5-HT2c and 5-HT1A receptor involvement in the acute effects of psilocybin in mice. In vitro pharmacological profile and modulation of thermoregulation and head-twich response Biomedicine & Pharmacotherapy August 29, 2022
- Psilocin, LSD, mescaline, and DOB all induce broadband desynchronization of EEG and disconnection in rats with robust translational validity Translational Psychiatry October 2, 2021
- Psilocybin—Mediated Attenuation of Gamma Band Auditory Steady-State Responses (ASSR) Is Driven by the Intensity of Cognitive and Emotional Domains of Psychedelic Experience Journal of Personalized Medicine June 19, 2022
- 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
- A comprehensive analysis of auditory event-related potentials and network oscillations in an NMDA receptor antagonist mouse model using a novel wireless recording technology. Physiological reports August 2018
and 2 more in the library