Effects of Mercury and Copper on the Olfactory Response in Rainbow Trout, Salmo gairdneri

Abstract
The effects of mercury and copper on the olfactory response of rainbow trout (Salmo gairdneri) were studied by perfusing HgCl2 and CuSO4 solutions through the olfactory organs while recording the olfactory bulbar electrical responses to the standard stimulant, L-serine.The olfactory response was depressed during exposure to mercury and copper. The lowest concentrations of mercury and copper needed to cause appreciable effects within 2 h were estimated at 0.10 and 0.008 mg/liter, respectively. The depression increased with increase in the concentration and exposure time of the heavy metals. Recovery of the olfactory response was slower with higher concentrations and longer exposure.The method is rapid, accurate, and sensitive, and can be applied to other toxic chemicals and fish species.