Different behavioural patterns induced by the dopamine agonist apomorphine analysed by multivariate statistics.

Exploratory behaviour was recorded in an automatic holeboard apparatus measuring activity, locomotion, rearing, hole exploration and corner restricted behaviour. Multivariate statistical methods were used to analyse the results. Low doses of the dopamine agonist apomorphine (0.01-0.1 mg/kg SC) dose-dependently reduced most variables measured, although the pattern of behaviour resembled that of normal animals. High doses of apomorphine (0.2-1.0 mg/kg SC) induced a qualitative change in the pattern of behaviour with a stereotyped locomotion and a reduced mean time of exploration of holes. The described methods for detection and statistical analysis of behaviour differentiates between the behavioural patterns induced by high and low doses of apomorphine and may be useful in finding and analysing patterns of drug induced behaviour related to various mechanisms of action.