Effects of imipramine, d-amphetamine, and tripelennamine on mouse and frog killing by the rat

Three centrally acting compounds, imipramine, d-amphetamine, and tripelennamine have been shown to block mouse killing by the rat when administered peripherally. In the present experiment the effects of these drugs on frog killing as well as mouse killing were examined. d-Amphetamine significantly increased the latencies of attacking and killing both prey. Tripelennamine and imipramine blocked the response to a frog. While most rats preferred to attack and kill frogs rather than mice as determined by a paired-comparison test, the drug effects were unrelated to those preferences. All 3 compounds significantly increased sniffing latencies to a frog but not to a mouse. The results suggest that drugs which block mouse killing may also block frog killing.