This study investigates inflammation in Parkinson's disease using special imaging techniques. The purpose is to understand how inflammation occurs and its mechanisms in Parkinson's disease. Participants will be in the study for about two visits. During these visits, they will have special brain scans called PET scans, which use a tracer to highlight inflammation areas in the brain. A compound called LPS will be given to cause a mild inflammation, and blood samples will be taken to measure inflammation levels.

Participants will undergo two visits, starting with a clinical examination and tests on memory and movement. They will have an MRI scan to take pictures of the brain. In the second visit, they will have two PET scans, one before and one after receiving LPS. Blood pressure and heart rate will be monitored after LPS is given. The study will include two blood draws to check inflammation levels.

• Who can participate: Participants should be 50-85 years old, able to give consent, and have good vision and hearing. They must not have major neurological or psychiatric disorders or a history of inflammatory or autoimmune diseases.
• Study details: Participants will attend two visits for PET scans, MRI scans, and blood tests. LPS will be given to study inflammation effects, with safety monitoring during the study.
• Study visits: The study requires 2 visits.