Parameters Relevant to the Experimental Production of “Stress” in the Mouse

The interactions between an unconditioned noxious stimulus (electric shock) and a conditioned stimulus (light) were systematically investigated in mice, utilizing change in body weight as a quantitative manifestation of “stress.” Merely moving mice from standard laboratory cages to experimental cages resulted in a significant decrease in weight gain. Mice subjected to periodic shock preceded by a stimulus light lost a greater amount of weight during the observation period than mice subjected to any of the other experimental conditions.