Stereotyped and aggressive behavior induced by sustained high dose of theophylline in rats.

tyrant No. 777196 from the Ministry of Education, Japan. AbstractRepeated administrations of high doses of theophylline to rats resulted in a series of stages which progressed as treatments were continued, i.e. hypoactivity, stereotypy, killing attack and automutilation, etc. Stereotyped behavior was con tinuous sniffing with backward locomotion, biting of the cage floor. standing on hind legs with forelimbs-flapping and turning somersaults in the cage. The aggressive behavior associated with theophylline treatment was that seen in affective aggression. The theophyllinized killers vigorously attacked animate as well as inanimate objects including rat-pups but never consumed their prey. Possible mechanisms of the ef fect of theophylline on aggressive behavior are discussed.