[11C]MK-6884 Positron Emission Tomography (PET) Tracer Validation Trial (MK-6884-001)

The purpose of this open-label, 3-part study is to investigate the safety and efficacy of \[11C\]MK-6884 as a positron emission tomography (PET) imaging agent for quantifying muscarinic 4 (M4) positive allosteric modulator (PAM) receptor density in brain regions of interest. The study will enroll healthy participants (Parts 1 and 2) and participants with Alzheimer's Disease (AD) (Part 3). The primary efficacy hypothesis is that the average intra-subject test-retest (T-RT) variability of tracer uptake in brain regions of interest is ≤20%.