The effects of cadmium exposure on shock-elicited aggression.

Abstract

Eighteen male Holtzman rats served as subjects. Prior to aggression testing, one group of 9 rats (Group CAD) was maintained on a .15% saccharin solution having 90 ppm cadmium for 133 days. Another group of 9 rats (Group SAC) served as a comparison group and were maintained during the same period on a .15% saccharin solution. The animals had access to the fluid on an ad libitum basis. Aggression, measured by number and duration of attacks on a target rod, was elicited via tail-shock on the day of testing. Each subject received an 8 minute period of tail-shock administration after a 5 minute habituation in the testing apparatus. During this time, 1.50 rnA shocks of 300 msec duration was administered at 3-second intervals. Each subject received a total of 160 shocks. The number of aggressive responses and the duration of aggressive responding was recorded for each animal. A nondirectional t-test with an alpha level of .05 was used to examine the data. Analysis of the data revealed group CAD made significantly more and longer aggressive responses than did Group SAC.