We are interested in determining whether ambient air pollutants impact the development of Parkinson's disease by increasing alpha-synuclein (alpha-syn) pathology via inflammation. After completing Specific Aim 2, wherein we found no differences between experimental groups in spread of alpha-syn, we discovered our collected nPM did not produce the expected neuroinflammatory changes. We repeated Specific Aim 2 mouse experiments with a new batch of nPM before SARS-CoV-2 quarantine. After restrictions were relaxed, we analyzed spread of alpha-syn using a novel AI, but found no difference between brains of nPM- and forced air-exposed mice. We are in communication with our collaborators at USC in order to plan and execute novel experiments to explore the effects of LPS-induced olfactory inflammation on spread of alpha-syn by histological (VARI) and biochemical (USC) analyses under continued quarantine and travel restrictions.