Date of Award

2016

Degree Type

Thesis

Degree Name

M.Sc.

Department

Biological Sciences

First Advisor

Zielinski, Barbara

Keywords

Copper, Olfactory, Sea lamprey, Toxicity

Rights

CC BY-NC-ND 4.0

Abstract

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.

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