Neurovascular and neuroimaging effects of the hallucinogenic serotonin receptor agonist psilocin in the rat brain
Neuropharmacology July 18, 2015 Aisling Spain, Clare Howarth, Alexandre A. Khrapitchev et al. 45 citations
Psilocin, the active metabolite of psilocybin, causes region-specific changes in brain activity measured by pharmacological MRI (phMRI). In rats, a high dose (2 mg/kg) increased phMRI signals in olfactory, limbic, and visual areas while decreasing signals in somatosensory and motor cortices. However, direct comparison of neuronal activity (local field potentials) and blood flow showed that psilocin reduced neuronal responses to sensory stimuli but enhanced the accompanying blood flow response. This dissociation indicates that phMRI signal changes reflect not only neuronal activity but also drug-induced alterations in neurovascular coupling, complicating the interpretation of hemodynamic neuroimaging data in pharmacological studies.