Differential effects of d- and l-amphetamine on mouse-killing behavior in rats.

Muricidal behavior in rats was selectively antagonized by both the d- and the l-isomer of amphetamine. However, d-amphetamine was approximately 8 times as potent as l-amphetamine as an inhibitor of mouse killing. The results of this study suggest that amphetamine antagonizes muricidal behavior in rats primarily via noradrenergic mechanisms. In addition, these results, as well as those in previous reports, imply that agents which modify the level of activity at central noradrenergic receptors may significantly alter the mouse-killing response of rats.