Evaluation of ()-, ()-, and ()-F-OF-NB1 for Imaging GluN2B Subunit-Containing -Methyl-d-Aspartate Receptors in Nonhuman Primates.

Despite 2 decades of research, no -methyl-d-aspartate (NMDA) glutamate receptor (GluN) subtype 2B (GluN1/2B) radioligand is yet clinically validated. Previously, we reported on ()-F-OF-NB1 as a promising GluN1/2B PET probe in rodents and its successful application for the visualization of GluN2B-containing NMDA receptors in postmortem brain tissues of patients with amyotrophic lateral sclerosis. In the current work, we report on the characterization of ()-, ()-, and ()-F-OF-NB1 in nonhuman primates.

Association of entorhinal cortical tau deposition and hippocampal synaptic density in older individuals with normal cognition and early Alzheimer's disease.

Sites of early neuropathologic change provide important clues regarding the initial clinical features of Alzheimer's disease (AD). We have shown significant reductions in hippocampal synaptic density in participants with AD, consistent with the early degeneration of entorhinal cortical (ERC) cells that project to hippocampus via the perforant path. In this study, [C]UCB-J binding to synaptic vesicle glycoprotein 2A (SV2A) and [F]flortaucipir binding to tau were measured via PET in 10 participants with AD (5 mild cognitive impairment, 5 mild dementia) and 10 cognitively normal participants.

Recently Abstinent Smokers Exhibit Mood-Associated Dopamine Dysfunction in the Ventral Striatum Compared to Nonsmokers: A [11C]-(+)-PHNO PET Study.

Introduction: Chronic nicotine exposure desensitizes dopamine responses in animals, but it is not known if this occurs in human tobacco smokers. Deficits in dopamine function are likely to make smoking cessation difficult. We used positron emission tomography (PET) brain imaging with the dopamine D2/3 receptor agonist radioligand [11C]-(+)-PHNO to determine if abstinent smokers exhibit less amphetamine-induced dopamine release in the ventral striatum than nonsmokers, and whether this was associated with clinical correlates of smoking cessation.

Assessment of test-retest reproducibility of [F]SynVesT-1, a novel radiotracer for PET imaging of synaptic vesicle glycoprotein 2A.

Purpose: Synaptic abnormalities are associated with many brain disorders. Recently, we developed a novel synaptic vesicle glycoprotein 2A (SV2A) radiotracer [F]SynVesT-1 and demonstrated its excellent imaging and binding properties in nonhuman primates. The aim of this study was to perform dosimetry calculations in nonhuman primates and to evaluate this tracer in humans and assess its test-retest reliability in comparison with [C]UCB-J.