Effects of Chlorpromazine On Dominance and Fighting Behavior in Rats

Abstract

AbstractForty male albino rats were paired and tested for five trials, one trial daily, in a dominance test situation. At the end of the five trials the dominant-submissive relationships of the pairs of animals were determined and the pairs assigned randomly to one of four groups. The criterion for dominance was total time in control of a food source during the trials. In the second five trials of the study, animals assigned to Group I, which served as a control group, were given injections of saline solution one hour before a dominance test. In Group II, submissive animals were administered .5 mg/kg. of chlorpromazine one hour prior to testing while dominant animals received saline solution. In Group III, dominant animals were given the drug while submissive animals received saline and in Group IV all animals received chlorpromazine. At the conclusion of the five drug trials, all pairs of animals were tested on five more trials during a port-drug stage. Results showed that: 1. When either a dominant or submissive animal of a pair was administered chlorpromazine, the drugged animals tended to control the food source for longer periods of time than did the non-drugged animals. Administration of chlorpromazine to both dominant and submissive animals of a pair caused both animals to spend more time in control of the food although the dominant animals tended to control the food source for longer periods of time than the submissive animals. 2. Fighting behavior was significantly reduced in all drug groups during the drug stage of the study.