Effects of Polystyrene Nanoplastics on Goldfish Olfactory Function

Abstract

Increased plastic pollution has begun to affect aquatic environments from oceans to freshwater streams with little signs of it slowing down since plastics are a cheap and durable resource to use for manufacturing. Due to increased plastic material waste in natural aquatic ecosystems, fish are threatened by the natural break down of these plastics into sizes and molecules that can be easily ingested and absorbed by tissue. When plastics are broken down and are present in the water, the absorption of these molecules becomes less regulated by tissue. Most of the studies regarding plastic effects at this point in time on aquatic organisms are focused on the transfer of plastic particles through generation. We hypothesized that polystyrene nanoplastic (PS NP) particles on Carassius auratus are incorporated through the nose to the brain, dampening olfaction and compromising several physiological responses associated with the sense of smell. We analyzed the physiological effect PS NPs have on the brain and olfactory system of C. auratus. After the fish were exposed to Nanocs 20 nm Fluorescein isothiocyanate (FITC) labeled PS NPs in water for 24 hours in a dark aquarium, or injected directly in the nose, several organs were dissected. The brain, nose, intestines, kidney, liver, and gills were all snap frozen, mounted in OCT and immediately cut at 20 μm on a cryotome before organs were viewed with fluorescent microscopy. PS NP fluorescence was observed mainly in the nose, brain and intestines while the other organs are still in the process of being analyzed. Accumulation of nanoparticles in the brain was stronger in hypothalamic and olfactory bulb areas. Behavioral and electrophysiology studies of olfactory function after nanoplastic exposure are under development to more closely look at the direct possible effects that nanoplastic materials in the brain might have on behavior. The observed fluorescence supported the existence and ability of PS NPs to infiltrate nervous tissues in C. auratus and points to a possible interference with the sense of smell.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.