Psychedelic 5-HT2A agonist increases spontaneous and evoked 5-Hz oscillations in visual and retrosplenial cortex.
bioRxiv : the preprint server for biology – July 06, 2025
Source: PubMed
Summary
While visual perception seems stable, brain waves actively shape what we see. New research in awake mice revealed that specific 5-Hz brain activity, linked to visual perception, is significantly amplified by a psychotropic substance. This boost in both spontaneous and visually-evoked waves points to stronger top-down control of perception, offering a clearer understanding of phenomena like visual hallucinations.
Abstract
Visual perception appears largely stable in time. However, psychophysical studies have revealed that theta waves (4-8 Hz) can modulate perception and have been linked to various cognitive states and functions. Neither the contribution of theta waves to cortical activity nor their impact during aberrant brain states have been resolved at high spatiotemporal scales. Here, using cortex-wide population voltage imaging in awake mice, we found that bouts of 5-Hz oscillations in the visual cortex are accompanied by similar oscillations in the retrosplenial cortex, occurring both spontaneously and evoked by visual stimulation. Injection of psychotropic 5-HT2AR agonist induced a significant increase in spontaneous 5-Hz oscillations, and also increased the power, occurrence probability and temporal persistence of visually evoked 5-Hz oscillations. This modulation of 5-Hz oscillations in both cortical areas indicates a strengthening of top-down control of perception, supporting an underlying mechanism of perceptual filling and visual hallucinations.