Effects of ketamine on depression-like behaviors of male offspring rat exposed to prenatal restraint stress

Abstract

Objective To investigate the effect of ketamine on depression-like behaviors at different developmental stages of offspring rat exposed to prenatal restraint stress (PRS). Methods Pregnant SD rats were randomly divided into control group (n=6) and PRS group (n=8). The dams of PRS group received three times(45 minutes/time)restraint stress every day. The anxiety-like and depression-like behaviors of the offsprings of the two groups were tested in the stage of juvenile, adolescence and early adulthood. Then the antidepressant effect of ketamine on prenatal stress rats at different developmental stages was observed. Results In the open-field test, the time in the central area of the offspring rats in PRS group at different developmental stages (juvenile(2.50±0.43)s, adolescence(9.17±1.05)s, early adulthood(8.33±0.92)s) were significantly lower than those of the control group((8.33±1.05)s, (19.17±1.06)s, (18.83±1.30 )s, all P<0.05). In the forced swimming test, the immobility time in the offspring rats of PRS group at the different developmental stages (juvenile(192.50±10.82)s, adolescence(182.75±10.12)s, early adulthood(199.88±9.20) s)were significantly higher than those of control group((76.00±19.00)s, (96.30±12.91)s, (108.30±10.98)s, all P<0.05). Ketamine could quickly and strongly reduce the immobility time of the offsprings exposed to PRS in the stage of adolescence and early adulthood (P<0.01), but the effect was weaker in the juvenile offsprings (P<0.05). Conclusion PRS leads to persistent anxiety-like and depression-like behavior in offsprings and ketamine exerts a good antidepressant effect on the offspring rats in the stage of adolescence and early adulthood. Key words: Prenatal restraint stress; Ketamine; Forced swimming test; Depression-like behavior