Induction of rage in rats by central injection of 6-hydroxydopamine

Intracisternal injection of 300 μg of 6-hydroxydopamine in male rats elicited a syndrome of hyperreactivity or hyperemotionality, i.e., rage, similar to that previously reported after septal or ventromedial hypothalamic (VMH) lesions. Specifically, rats showed increased resistance to capture as well as increased number and magnitude of startle responses compared to vehicle injected or normal controls. As with septal but not VMH lesions, this rage subsided with repeated testings (handling). These findings are discussed with regard to the possible importance of brain neurotransmitters in the expression of behaviors.