Is apomorphine an agent inducing stereotypy

Abstract

During the past 10 years a lot of material has been published on the behavioural actions of amphetamine and apomorphine both of which are known to produce a variety of behavioural patterns, some in common, in laboratory animals (Randrup, Munkvad and Udsen, 1963; Ernst, 1967; Fog, 1969: Randrup and Munkvad, 1968). The continuous and purposeless behaviours like ‘sniffing’, ‘gnawing’ and ‘biting’ produced by these two agents have been described as ‘compulsive syndrome’ or ‘stereotyped behaviour’ (Randrup and Munkvad, 1970). Unlike these behaviours, the horizontal and vertical activities in special circumstances such as the Open Field test and Lat’s Instrument after administra­tion of amphetamine have also been described as stereotyped actions (Dandiya, Gupta and Gupta, 1970; Lat, 1965). Since stereotyped actions in animals with certain relationships to the human psychosis, may serve as experimental models, the studies conducted to understand the neuronal mechanism of these patterns have not only identified the brain structures regulating these behaviours but also the neurotransmitter substance responsible for the genesis of this compul­sive syndrome. The nigro-striatal dopaminergic system has been recognised as being mainly responsible for the induction of stereotyped behaviours (Scheel-Kruger and Randrup, 1967; Randrup and Munkvad, 1966, 1968, 1970). Our experiments have also shown that the vertical stereotypy in the Open Field test is a positive function of brain dopaminergic system and agents, that is, l-DOPA, benztropine, amantadine, which have predominant action on this brain system were able to produce vertical stereotypy (Kulkarni and Dandiya 1972; 1975a).