Further Aspects of Aggressive Behavior Induced by Sustained High Dose of Theophylline in Rats*

Abstract

Sustained injection with a high dose of theophylline increased aggressiveness in rats in both behavioral ratings and paired fighting. In the latter test, 50% of theophyllinized pairs took the fighting position following a hand-clap and the 75% of treated rats were dominant over control partners. In the open field test, the theophyllinized rat discharged fewer boluses, but there was no change in ambulatory activity. The present results support the finding in our previous study that demonstrated the production of affective aggression with the chronic treatment of theophylline.