University Archives

Plastic pollution has emerged as an increasingly urgent environmental concern, yet its effects on aquatic organisms remain largely obscure. This study examined the impact of microplastic and nanoplastic exposure on olfactory function in fathead minnows (Pimephales promelas). Fish were exposed for 28 days to either control, microplastic, or nanoplastic conditions, after which behavioral assays were conducted to evaluate responses to odorants. In the second phase of the experiment, neural activation within the olfactory epithelium was quantified following odorant exposure. Phosphorylated extracellular signal-regulated kinase (pERK) immunostaining was used to visualize and measure recently activated olfactory sensory neurons. The number and distribution of activated neurons were compared across control, micrplastic-, and nanoplastic-exposed fish to assess potential differences in olfactory signaling. By quantifying activated cells across treatment groups, we aimed to determine whether exposure to plastic particles alters the ability of olfactory receptors to detect and respond to odorant molecules. We hypothesized that fish exposed to microplastics and nanoplastics would exhibit reduced neuronal activation relative to controls, potentially due to receptor damage or impaired odorant binding. Understanding how emerging environmental contaminants disrupt sensory systems is critical for assessing their ecological consequences. The broader objective of this study is to evaluate how plastic pollution may interfere with essential sensory processes and associated behaviors in aquatic organisms experiencing increasing anthropogenic change.