Septal damage in infant and adult rats: Effects on activity, emotionality, and muricide

Is the concept of ‘personality’ relevant to the study of animal aggression?

“…Various brain manipulations were found to result in an actual initiation of mousekilling behaviour only in those rats that had not been given any prior experience with mice, and a bilateral lesion of the medial amygdala was shown to abolish the preventing effect of a prior familiarization with mice (Vergnes, 1981). Early amygdaloid lesions which produce a lasting hyperreactivity were shown to have a similar effect: a prolonged familiarization with mice, which in the intact rat prevents any subsequent manifestation of mouse-killing behaviour, proved to be without any effect in the amygdaloid-lesioned animals, since most of them killed mice when adult (Eclancher and Karli, 1979a).…”

The interaction between the self and the environment – a two way traffic due to the brain

“…In our extensive study of interspecies aggression, the probability of appearance of 'mouse-killing behaviour' was found to be lower in group-reared than in isolation-reared rats, but this difference was no longer observed when all the animals had undergone a septal lesion at the age of 7 days. 33 In the human infant, the differential profile of reactivity to stimulation described by Kagan can also be modulated by the dialogue carried on with the social milieu, and both the amygdala and the septum are likely to be involved in the mediation of these experience-induced effects.…”