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.

Topic Healthy Subjects
Compound Psilocybin
Country Denmark
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Trial Details



Trial Number

Sponsors & Collaborators

University of Copenhagen
The Neurobiology Research Unit (NRU) at Copenhagen University Hospital have been carrying clinical and preclinical research with psychedelics since 2017.

Papers

Psilocybin’s effect on human brain synaptic plasticity
This pre-print double-blind placebo-controlled trial (n=15) found that healthy participants who had a psilocybin-induced psychedelic experience in a therapeutic-like room exhibited more intense mystical-type experiences, longer-lasting psychological benefits, and greater increases in synaptic density than those dosed inside an MRI scanner, indicating that psilocybin's neuroplastic effects are modulated by environmental context.

Navigating the chaos of psychedelic neuroimaging: A multi-metric evaluation of acute psilocybin effects on brain entropy
This brain imaging study (n=28) evaluated the acute effects of psilocybin on 12 previously reported brain entropy metrics in healthy participants. It found a positive association for Shannon entropy of path-length and instantaneous correlation distributions, while no significant effects were observed for seven of the 12 metrics, and concluded that the acute effects of psychedelics on brain entropy are nuanced and that 'brain entropy' is not a singular construct.

Psilocybin-Induced Mystical-Type Experiences are Related to Persisting Positive Effects: A Quantitative and Qualitative Report
In this open-label study (n=28), participants were administered medium-high doses of psilocybin (12-30mg) and reported the intensity of their experience using the Mystical Experience Questionnaire (MEQ). The Persisting Effects Questionnaire (PEQ) was administered 3-months after psilocybin administration. It was found that the total MEQ score was positively correlated with the later emergence of positive PEQ effects. Using natural language pre-processing, participants' qualitative reports of their experience were analysed to provide descriptions of the "Complete Mystical Experience."

Psilocybin-induced changes in brain network integrity and segregation correlate with plasma psilocin level and psychedelic experience
This fMRI study (n=15) investigated the effects of psilocybin (14-21mg/70kg) on the brain and found that the higher the psilocin (active metabolite of psilocybin) and subjective drug experience (SDI) correlated with lower network integrity and segregation (less top-down, more bottom-up).

Data attribution

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