Psilocybin Prolongs the Neurovascular Coupling Response in Mouse Visual Cortex
OpenAlex – July 31, 2025
Source: OpenAlex
Summary
Psilocybin, a potent hallucinogen and alkaloid, profoundly alters brain function. Neuroscience reveals this psychedelic drug, which can be chemically synthesized, prolongs blood flow increases in the visual cortex without changing neural activity in awake mice. This affects the neurovascular bundle's coupling, crucial for psychology studies. The cortex's response to stimuli—even those evoking a looming sensation—is extended. Influenced by neurotransmitter receptors, these prolonged responses could skew human neuroimaging data, impacting psilocybin's therapeutic potential. Accounting for this is vital for accurate drug studies.
Abstract
Abstract Psilocybin has profound therapeutic potential for various mental health disorders, but its mechanisms of action are unknown. Functional MRI studies have reported the effects of psilocybin on brain activity and connectivity; however, these measurements rely on neurovascular coupling to infer neural activity changes and assume that blood flow responses to neural activity are not altered by psilocybin. Using two-photon excited fluorescence imaging in the visual cortex of awake mice to simultaneously measure neural activity and capillary blood flow dynamics, we found that psilocybin administration prolonged the increase in visual stimulus-evoked capillary blood flow – an effect which was reduced by pretreatment with a 5-HT 2A R antagonist – despite not causing changes in the stimulus-evoked neural response. Multi-modal widefield imaging also showed that psilocybin extends the stimulus-evoked vascular responses in surface vessels with no observed effect on the population neural response. Computational simulation with a whole-brain neural mass model showed that prolonged neurovascular coupling responses can lead to spurious increases in BOLD-based measures of functional connectivity. Together, these findings demonstrate that psilocybin broadens neurovascular responses in the brain and highlights the importance of accounting for these effects when interpreting human neuroimaging data of psychedelic drug action.