Effects of continuous copper exposure and calcium on the olfactory response of fathead minnows.
The current gill-based Biotic Ligand Model (gbBLM) is an acute-toxicity model used to predict site-specific safe copper (Cu) concentrations. Recent effort to develop a chronic BLM has focused on the olfactory epithelium. To further this effort, the current study looked at the effect of varying Cu concentration and exposure duration on Cu-induced olfactory dysfunction, and whether calcium (Ca) protected against Cu-induced impairment as it does at the gill. Fathead minnows (Pimephales promelas) were treated with five Cu concentrations for varying exposure durations in hard and soft water. A neurophysiological technique, electro-olfactography (EOG), was employed to determine the level of olfactory dysfunction. At the low, ecologically relevant Cu concentrations tested there was significant inhibition of EOG function; however, over time there was at least a partial recovery of olfactory function, despite the continuous Cu exposure. Calcium did not appear to protect against Cu-induced olfactory dysfunction; and even alone, Ca appeared to interfere with the olfactory response to the amino acid L-arginine. Safe copper concentrations as predicted by the gbBLM, chemosensory-based BLMs, the USEPA BLM, and hardness-adjustment equations based on the exposure waters were not entirely protective against olfactory dysfunction.
Department of Biology, Lakehead University, Thunder Bay, Ontario, P1B 8L7 Canada.
William A
WA
Dew
Chris M
CM
Wood
Greg G
GG
Pyle
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D003300:Copper / Q000633:toxicity*; D003530:Cyprinidae / Q000502:physiology*; D005880:Gills / Q000187:drug effects; D012903:Smell / Q000187:drug effects*
D003300:Copper; D002118:Calcium