Odor-mediated runway performance is affected by cadmium ingestion.

Abstract

Eighteen male Holtzman rats served as SUbjects. One group of 9 rats (Group CAD) was maintained on a .15 % saccharin solution having 90 ppm cadmium chloride for 80 days. Another group of 9 rats (Group SAC) served as a comparison group and was maintained during the same period on a .15 % saccharin solution. All animals had access to the fluid on an ad libitum basis. Group CAD and SAC received double alternation, reward(R)-nonreward(N) runway training. When only olfactory cues could be used as discriminative stimuli (Phase 1), just the SAC animals were capable of mastering the RRNNRRNN pattern. When a tactile discriminative stimulus was added (Phase 2), both groups of animals displayed appropriate patterned responding. Removal of the tactile cue (Phase 3) resulted in the immediate disruption of patterned responding in CAD animals, A separate split-plot ANOVA incorporating groups (CAD vs. SAC) as a between-subjects factor and days and type of trial (RI, NI, R2, and N2) as within-subjects factors was performed on the run and goal-approach speeds for the last 3 days of Phase 1. Phase 2. and Phase 3. The results of these analyses support the view that chronic cadmium exposure inhibits olfactory ability; Group CAD was clearly inferior to Group SAC in acquisition of the olfactory discrimination.