Tolerance of the lamprey olfactory system to copper concentrations found in roadway runoff waters to the Great Lakes

摘要

In fishes, olfaction mediates a variety of behaviours necessary for survival and reproduction. Environmental contaminants, specifically copper, are able to disrupt a broad range of olfaction-mediated behaviour, and can cause long-lasting damage due to physiological and genetic changes at low concentrations. To investigate effects of copper on olfaction, the sea lamprey (Petromyzon marinus), an invasive fish species in the Laurentian Great Lakes, was exposed to environmentally relevant copper concentrations of 0, 5, 10 and 30 µg Cu-L. Three techniques were used to measure the effects of exposure of contamination: (i) immunohistochemical analysis of olfactory epithelium, (ii) local field potential recordings in odor-evoked responses, and (iii) gene transcription response to copper toxicity. Impairment in olfactory epithelium was demonstrated through loss of dendritic extension of olfactory sensory neurons, as well as a dose-dependent reduction in olfactory response to male sex pheromone odors. Differentially expressed genes were identified following exposure in each concentration. Low levels of copper measured in urban waterways were found to impair olfactory senses of the sea lamprey.