[Aggressive behaviour induced by apomorphine: relations with some elements of the behavioural profile and with the...

Aggressive rats could be differentiated from non-aggressive rats on a lower rate of rearing reactions in the open-field activity, as well as on a weaker aptitude for learning, increasing with the complication of the test. The two groups of rats had comparable activity, and a comparable response to pain. Apomorphine decreased the number of rearing reactions and defecations on open-field activity in the same manner in non-aggressive rats as in aggressive animals. In the usual housing conditions, apomorphine increased similarly locomotor activity in both groups, but in observation cages of "emotional" type, the increase was much more pronounced in aggressive rats than in non-aggressive animals.