Effects of dietary changes on muricide activity in adult and young rats.

Recent works have showed different interrelations between dietary tryptophan intake and aggressive behaviour in different groups of rats. In this experiment the AA. have treated thirty Sprague-Dawley rats (15 youngs and 15 adults) with tryptophan free-diet, during eight weeks. Muricide activity was weekly controlled; daily food intake for all group was recorded. Young rats feeding tryptophan free-diet and young rats pairfed controls showed aggressive behaviour at the sixth week of treatment. Adult rats did not show any changes of mouse killing during the whole period of experiment.