Defence and Territorial Behaviour dissociated by Hypothalamic Lesions in the Rat

Abstract

IT has been pointed out that much of the literature on brain mechanisms of aggression fails to distinguish between different kinds of aggressive behaviour, and that this may account for some of the apparent contradictions in different publications¹. In the experiments reported here the effects of hypothalamic lesions were measured on two different types of aggressive behaviour: defence behaviour, which consists of a defensive upright posture and boxing in the shock box; and territorial behaviour, which consists of the offensive side posture and the full attack posture with biting and kicking by a socially isolated home rat against an intruder. These postures associated with social interactions are quite stereotyped in the rat. They are also present in modified form in other rodents and have been illustrated and catalogued previously².