Cellular Pharmacology • October 20, 2026
5-HT2A Receptor Agonism: Cellular Mechanisms of Psilocybin in Layer V Pyramidal Neurons
Psilocin selectively targets 5-HT2A receptors on layer V pyramidal neurons, inducing asynchronous glutamate release and altering cortical signal processing.
Distribution of 5-HT2A Receptors in the Human Cortex
The 5-HT2A receptor subtype is densely concentrated in high-level associative cortical areas, particularly within layer V pyramidal cells of the prefrontal cortex, anterior cingulate, and visual processing regions.
Glutamatergic Transmission and Asynchronous Firing
Activation of 5-HT2A GPCRs by psilocin increases Gq/11 protein intracellular signaling, leading to phospholipase C (PLC) stimulation and IP3/DAG cascades. This triggers an inflow of calcium ions and local glutamate release from thalamocortical afferents.
Sensory Gating and Synesthetic Perceptions
The resulting increase in cortical excitability alters sensory gating mechanisms in the thalamus, allowing auditory, visual, and somatosensory inputs to cross-activate, giving rise to enhanced sensory vividness and synesthesia.