Increased volume and neuronal number of the basolateral nuclear group of the amygdaloid body in aggressive dogs

Involvement of the basolateral nuclear group (BNG) in pathological canine aggression was assessed by stereological determination of the volume of the BNG and quantification of the numerical density and total number of BNG neurons in normally behaving and aggressive dogs. A bilateral BNG enlargement of 40% was observed in the aggressive group. This enlargement appeared to be caused by a significantly increased number of BNG neurons. Other alterations such as an increased vessel density, oedema and scar tissue were not observed in any of the examined BNGs. The potential role of neurotrophins and stress hormones in the increased number of BNG neurons is discussed.