The Neurobiological Effect of 5-HT2AR Modulation
The investigators wish to investigate neurobiological effects of serotonin 2A receptor modulation in healthy volunteers, contrasting effects of an agonist (psilocybin) and an antagonist (ketanserin). Magnetic resonance imaging (MRI) and positron emission tomography (PET) will be used as neuroimaging tools. This project applies an experimental medicine strategy coupled with human functional and molecular neuroimaging to elucidate the effects of 5-HT2A receptor (5-HT2AR) modulation on brain function and mood in healthy individuals. We compare psilocybin (5-HT2AR agonist) and ketanserin (5-HT2AR antagonist) effects on brain function to identify neural mechanisms mediating the clinical effects of psilocybin and, more broadly, to establish this comparative strategy as a pathway for delineating pharmacological effects on the brain in humans.