Ava RohrbaughBiologyacr5882@psu.eduADVISORSPatrick DrewAssociate Director of the Neuroscience Institutepjd17@psu.eduDenver GreenawaltGraduate Studentdig5276@psu.eduKEYWORDSNeurotoxicity, polystyrene, plastics/nanoplastics, trigeminal nerve, endocytosis, air pollution, fluorescenceABSTRACTPlastic is a principal material for most commercial products including water bottles, packaging, and other single-use items. These plastic products will naturally experience mechanical, chemical, and photodegradation which will result in the formation of macro and microplastics. Microplastics can be further degraded into nanoplastics which are toxic to organisms due to their ability to enter more invasive cellular spaces. Nanoplastics can also become airborne and taken in by an organism through the nasal pathway. The reality that microplastics are of increasing concern as a pollutant is not disputed, however, the pathways by which our body internalizes plastic particles and the effects of nanoplastics on our cells need to be further investigated. My project investigates a possible intracellular pathway by studying the in vivo translocation of polystyrene nanoparticles in a mouse model. The goal of this project is to determine if nasally administered polystyrene nanoparticles are endocytosed into the trigeminal nerve (maxillary branch) and translocated to the trigeminal ganglion which is the junction of the trigeminal nerve branches. My contribution to this project was to prepare solutions for nasal administrations, process perfused mice, extract trigeminal ganglia, section samples using a cryostat, and view the trigeminal ganglia on a confocal microscope. The polystyrene nanoparticles I used to model environmental nanoplastics are fluorescently labeled and were imaged in 40um transverse whole-skull sections that included the trigeminal ganglia.