[The general behavioral characteristics of rats selected for the duration of the passive defense reaction and for the threshold of neuromuscular excitability].

Two strains of rats, (GC) ("genetic catalepsy"), and (Lt), ("low-threshold") proposed as models of human psychopathological symptoms, were compared. Characteristics of "activity" and "emotionality" in the open field were practically the same in the strains studied. Disturbance of motor plasticity seemed to be for the lack of circular movements in free behaviour. Injections of apomorphine induced oppositely directed effects on the number of yawns in GC and Lt rats. Galoperidol effect was cataleptogenic in both the strains. The similarity in open field behaviour parameters and the effects of apomorphine and galoperidol appeared to be underlain by a large number of common features in nervous system organization.