Effect of post-weaning isolation on anxiety- and depressive-like behaviors of C57BL/6J mice

Effects of post-weaning isolation on depressive- and anxiety-like behaviors in rodents have been well studied in the past. However, few studies included both sexes in a single experiment to study the sex difference in this animal model. The present study investigated the effect of post-weaning isolation on anxiety- and depressive-like behaviors in both male and female C57BL/6 J mice. Mice were individually or grouped housed from postnatal day 21 for 5 weeks until behavioral tests began. The results showed that social isolation resulted in increased anxiety in the open field. Isolated-reared female, but not male mice showed an increased transition between two compartments in the light-dark box and a decreased immobile time in the forced swim test. We conclude that post-weaning isolation has a sex-specific effect on emotional behaviors.