Response to novelty of various types in laboratory rats.

One purpose of the two studies reported here was to examine the reactions of rats to changes in the spatial arrangement of a familiarized environment under low stress conditions. The second purpose was to test the role of rats' experience with novelty. In Experiment I the novelty was manipulated by introducing new tunnels into one zone of the experimental chamber. The introduction of novelty took place after 11 habituation sessions. In Experiment II in the course of habituation sessions the experimental group of rats was subjected to a persistent change of tunnel arrangement in the experimental zone, whereas for the control group nothing changed. All animals reacted to the novelty with increased time spent in the experimental zone and decreased time spent in other zones. Both experiments show that under low stress conditions rats demonstrate a positive response toward novelty and that their previous experience with novelty does not affect that reaction.