Different reaction patterns in individually and socially reared rats during exposures to novel environments

Individually and group-reared male rats were behaviourally compared after various periods of different housing, (i) during a first exposure to the new environment, and (ii) after habituation (two repetition trials) to the situation, during a fourth exposure in a slightly modified test-box. Compared to group-housed controls an elevated locomotor activity upon the first exposure and a reduced reaction in response to the slight modifications were found in individually housed rats.