The Johns Hopkins University was awarded a $670,600 Project Grant from the National Institute of Neurological Disorders and Stroke (NINDS) under the Extramural Research Programs in the Neurosciences and Neurological Disorders (CFDA 93.853) federal grant program. The project aims to better understand the relationship between microglial activation, measured using a novel radioligand [11C]CPPC, and the severity of motor and cognitive symptoms in Parkinson's disease (PD) and PD-mild cognitive impairment (PD-MCI). Specifically, the project will: 1) Determine if CSF1R density, as measured by [11C]CPPC, is increased in PD patients with greater motor and cognitive dysfunction compared to healthy controls, and 2) Assess whether CSF1R binding with [11C]CPPC is associated with peripheral blood markers of immune function and neurodegeneration that correlate with inflammation and disease progression. This research seeks to elucidate the role of microglia in the pathogenesis of PD and PD-related cognitive impairment, with the goal of identifying novel targets for therapeutic intervention. The award period runs from January 1, 2025 to December 31, 2029.