The Importance of a Novel Object in Exploration in High and Low-Saccharin Rats

Abstract

Exploration is a naturally occurring response to a change in environment for rats. This study seeks to learn more about the role of the appetitive motivation of a novel object on the behavior and exploration of rats in an open field. These rats have been selectively bred based on their selection phenotype regarding saccharin. LoS rats were bred for phentoypically lower saccharin ingestion while HiS rats were bred for phentoypically higher saccharin ingestion. LoS rats are more emotionally reactive and in general more anxious. In this study, 10 subjects were observed in an open field for three consecutive days with the presence of a novel object (a lego pyramid) while 10 subjects were observed in an open field for three consecutive days without the presence of a novel object in the center. On the fourth day, the object was either removed or added, respectively. Amount of time and distance traveled within specifically designated zones of the open field were used as a measure of exploratory behavior in subjects. Boli were also counted as a partial indicator of stress or anxiety. Removal rats spent more time in the center after the object was removed than Addition animals did when it wasn't there.