Play Fighting in Kindling-prone (fast) and Kindling-resistant (slow) Rats: Potential Genetic Controls over the Components of Play

Play fighting in kindling-prone (FAST) and kindling-resistant (SLOW) rats: Potential genetic controls over the components of play. Even though the behavioral components of play fighting have been well characterized in the rat, little is known about the underlying neurobehavioral mechanisms that control them. FAST and S L O W lines of selectively-bred rats were used to determine whether the components of play fighting were dissociable. Differences in their respective play profiles suggest that there are genetic differences in the expression of different components of play. The effects of gene-environment interactions on the components of play suggest that playful attack and playful defense may be differentially labile, and that socially-relevant environmental manipulations may have a greater impact on social interactions in adulthood than in the juvenile phase. Furthermore, these findings suggest that the genetic constraints on each of the components of play fighting give each component a unique pattern of context-dependent change. Future experiments using FAST and SLOW, as well as other selectively-bred lines of rats may provide insight into the proximate mechanisms regulating play fighting.