Age effects on the social interaction test in early adulthood male rats

The effects of age on active and passive social interaction were studied in Wistar rats using the social interaction test (S.I.T.). Individual behaviors such as ambulation, rearing, and defecation were also studied. Despite the widespread use of the S.I.T. in anxiety research, the effects of age on the S.I.T. have not been studied thoroughly. Male Wistar rats of 75, 135, and 180 days old were used. Our results showed age effects on active social contact, passive social contact, ambulation, rearing, and defecation. At 135 days old, animals presented the lowest scores on active social behavior and the highest scores on defecation. Moreover, exploratory behavior measured by ambulation and rearing decreased with age. These results suggest that age could be a relevant variable in the social interaction test.