Interaction between isolation rearing and social development on exploratory behavior in male rats
Publication Type: |
Journal Article |
Year of Publication: |
2005 |
Authors: |
Hiroyuki Arakawa |
Publication/Journal: |
Behavioural Processes |
Keywords: |
anxiety, exploratory behavior, isolation-rearing, rats, social development |
ISBN: |
03766357 |
Abstract:
The effect of isolation on exploratorybehavior has been shown to differ depending on the developmental stages of malerats. However, there has been little systematic comparison of the frequencies and the patterns of exploratorybehavior across the developmental stages. The present study assessed the frequencies of exploration using the emergence test and exploratory patterns in the open-field test in three developmental stages of malerats: juvenile, post-puberty, and adult. A lower propensity for exploration was observed in rats isolated during the juvenile stage, as assessed by increased latency and decreased duration of exploratorybehaviors compared to pair-reared rats, and this tendency was maintained in adulthood. Altered patterns of exploratorybehavior were demonstrated both in rats isolated in adulthood, who showed an increased active pattern, and those pair-reared following puberty, who shifted to a more passive pattern. However, rats isolated during the juvenile stage did not change their exploratory patterns following puberty. These results suggest that the changes in the exploratory pattern, which can be observed in adulthood, are associated with the emergence of adult-like dominance relationships. Juvenile-isolated rats did not show these changes following puberty, suggesting the importance of socialinteraction as juveniles for the ontogenetic emergence of behavioral flexibility implicated in the regulation of exploratory patterns.