1 Department of Comparative Physiology, Utrecht University, Utrecht, The Netherlands
2 Rudolf Magnus Institute for Neurosciences, Utrecht University, Utrecht, The Netherlands
Housing conditions may affect the behaviour of rats in the home cage, but also in behavioural testing outside the home cage. To assess the impact of a newly developed, enriched, housing system on these two aspects of behaviour, two strains of rats were observed in either standard housing conditions or the new housing system. The two strains of rats were Wistar (U:WU(CPB); n=39) and a so-called "wildtype" strain (n=21) which is said to be similar in behaviour to rats in the wild. Behaviour was observed in the home cage (focal animal sampling method, 30 min. per animal) using "The Observer 3.0". To test behaviour outside the home cage all animals were placed on an Elevated Plus Maze for 5 minutes. The results indicate that the new housing system was able to enhance active behaviour and reduce agonistic behaviour in the home cage in both strains. It also affects behaviour on the Elevated Plus Maze of the Wistar strain but not the "Wildtype" strain.