Motivational systems or motivational states: Behavioural and physiological evidence

This paper will critically discuss the available behavioural and neurobiological evidence for the existence of motivational systems and motivational states on the basis of our studies on aggressive behaviour in male rats and mice. Three types of evidence will be discussed. First, some behavioural studies will be evaluated indicating that aggressive behaviour can be considered as part of a cluster of behaviours used to cope actively with environmental challenges. Second, it will be argued that coping styles are based upon different neurochemical brain states, which may be a reflection of motivational states. Third, the neurobiological evidence will be discussed for the existence of identifiable neuronal systems for certain behaviour systems, on the basis of studies on male sexual and aggressive behaviour. Finally, the relevance of the concept of coping styles to stress-pathology will be discussed briefly. (C) 1997 Published by Elsevier Science B.V.