Human Cortical Serotonin 2A Receptor Occupancy by Psilocybin Measured Using [C]MDL 100,907 Dynamic PET and a Resting-State fMRI-Based Brain Parcellation.

Psilocybin (a serotonin 2A, or 5-HT, receptor agonist) has shown preliminary efficacy as a treatment for mood and substance use disorders. The current report utilized positron emission tomography (PET) with the selective 5-HT receptor inverse agonist radioligand [C]MDL 100,907 (a.k.

Brain PET Imaging of α7-nAChR with [18F]ASEM: Reproducibility, Occupancy, Receptor Density, and Changes in Schizophrenia.

Background: The α7 nicotinic acetylcholine receptor increasingly has been implicated in normal brain physiology, as well as in neuropsychiatric disorders. The highly cortical distribution of α7 nicotinic acetylcholine receptor suggests a role in cognition.

Methods: We expanded the first-in-human PET imaging of α7 nicotinic acetylcholine receptor with [18F]ASEM from 5 to 21 healthy nonsmoking volunteers and added a feasibility study in 6 male patients with schizophrenia.

Environmental influences on neural systems of relational complexity.

Constructivist learning theory contends that we construct knowledge by experience and that environmental context influences learning. To explore this principle, we examined the cognitive process relational complexity (RC), defined as the number of visual dimensions considered during problem solving on a matrix reasoning task and a well-documented measure of mature reasoning capacity. We sought to determine how the visual environment influences RC by examining the influence of color and visual contrast on RC in a neuroimaging task.