Gentled and non-handled rats in a stressful open-field situation; differences in performance.

Open-field behaviour of individually gentled and non-handled adult Wistar rats in a stressful test situation (loud noise with bright light) was studied. The behaviour on the whole of the two groups differed significantly. While the gentled rats showed mainly signs of stress and explorativity, signs of fear beside stress and, on later trials, explorativity were typical of the non-handled animals. On later trials the behaviour of the non-handled rats neared to that of the gentled ones. In the behaviour of the gentled rats there was but little change as a function of trials. We suggest that individual gentling, beside minimizing fear of human contact, also increases the stability of the rat's reactions.