ABSTRACT
Are aggressive behaviours inhibited similar to the way tryptophan hydroxylase is inhibited by para–chlorophenylalanine (PCPA) or raphe neurons are inhibited by microiontophoresed lysergic acid diethylamide (LSD) (e.g., Koe and Weissman 1966, Aghajanian et al., 1968)? How useful is the extrapolation of an inhibitory process from the molecular and cellular level to the behavioural level? When Brodie and Shore (1957) suggested an inhibitory function for brain 5–HT on behaviour and autonomic nervous system activity, they were guided by the concept of W.R.Hess (1954) who proposed a trophotrophic subcortical system guiding recuperative, sedative behaviours that are associated with increased parasympathetic output. 5–HT was postulated to serve as the critical neurotransmitter in this system. An opposing ergotrophic system was proposed to subserve behavioural arousal accompanied by sympathetic activation. The concept of serotonin as a trophotrophic neurotransmitter has been applied to the neural control of aggressive behaviour up to the present (e.g., Valzelli, 1982; Eichelman, 1979; Pucilowski and Kostowski, 1983).
