Response to spatial and nonspatial change in wild (WWCPS) and Wistar rats

The purpose of the experiment was to investigate the effects of domestication on exploration in rats. The comparison was made between wild Warsaw-Wild-Captive-Pisula-Stryjek (WWCPS) rats and Wistar laboratory rats. The study used a purpose-built maze divided into zones connected with a corridor. Objects were placed in two out of four zones. Their location and shape were subject to experimental manipulation. Transporter used to move rats to the maze provided the opportunity for spontaneous exploration of the experimental arena. Rats were subjected to a series of 10 sessions (habituation), followed by a spatial or nonspatial change in the experimental arena, after which another 5 experimental sessions were conducted. The study revealed that wild rats had much higher exploration latency than their laboratory counterparts. At each analyzed stage, WWCPS rats spent much more time in the transporter than Wistar rats. Wistar rats spent much more time during the experiment on object interaction in the experimental arena. In post-manipulation sessions, however, it was wild rats that explored object zones relatively longer than laboratory rats. No differences in the animals' behavior depending on the type of change were observed. Results suggest that wild rats tend to explore much more cautiously than laboratory rats and are more sensitive to changes in their environment. The underlying cause of these differences is likely to be the higher level of stress in wild rats, resulting from threats in their natural habitat.