Five strains of rats, two outbred (Sprague-Dawley and Holtzman) and three inbred strains (Buffalo, Lewis, and Fisher), received subcutaneous implants of either morphine or placebo pellets. The naloxone-precipitated opiate ...

The two experiments in this study investigated overtraining effects and frustration effects during extinction of combined runway-barpress responding by albino rats The chain of runway-barpress responding provided discrete ...

108 rats were given training in an approach-avoidance spatial conflict situation. Following completion of training, Ss were tested for retention of the avoidance response after intervals of 15 min., 3 hrs., or 24 hrs. ...

This study investigated acquisition of a shuttlebox avoidance task using high (1.00 ma) and low (0.25 ma) shock levels, following different durations of treatment with dl- parachlorophenylalanine (PCPA), a depletor of brain ...

Twenty-four albino rats were tested in a 5' straight alley on a double alternation pattern of reward and non- reward--a pattern which previous work has shown to be impossible for the rat to perform on the basis of internal ...