Effects of combining pilocarpine, d-amphetamine, and either a free feeding schedule or cyclic food deprivation on mouse killing by rats.

The combination of a drug which suppresses mouse killing by rats (d-amphetamine) , a drug which activates mouse killing (pilocarpine), and either ad-lib food or a 24-hour cyclic food deprivation schedule were examined for their effects on the mouse-killing response by rats (N = 53). Results showed that the presence of d-amphetamine prevented the activating effects of pilocarpine in rats with a fairly high killing propensity regardless of whether they were on the ad-lib food or the deprivation schedule. The study suggests that a drug which affects both eating behavior and mouse killing is more effective in determining behavioral outcomes than a drug which affects only mouse killing.