Effects of maternal deprivation on stress response and efficacy of escitalopram in adult rats

Abstract

Objective To investigate the effects of maternal deprivation on chronic stress-induced depression behavior and its characteristics in adult rats, and to evaluate the effects of maternal deprivation on the efficacy of escitalopram. Methods Newborn SD male rats were randomly divided into control(C) group, maternal deprivation (MD) group, chronic unpredictable stress (CUPS) group, maternal deprivation and chronic unpredictable stress (MD+ CUPS) group. Rats in control group received no experimental handling.Rats in MD group and MD+ CUPS group received maternal deprivation from the lst day after birth for 14 days.Rats in CUPS group and MD+ CUPS group received chronic unpredictable stress from 10 th weeks after birth for 28 days. Screened the rats with depression behaviors and treated them with escitalopram for 4 weeks. Results The incidence of anhedonia was significantly different among 4 groups (χ2=143.24, P CUPS group (40.98%) > MD group (17.11%) >C group (4.17%), P<0.0083). The incidence of behavioral despair was significantly different among 4 groups (χ2=70.34, P<0.05). Pairwise comparison showed the incidence of behavioral despair in MD+ CUPS group (43.43%) and CUPS group (39.34%) were significantly higher than that in MD group (13.51%) and C group (3.33%), but no difference was observed between MD+ CUPS and CUPS group (P<0.0083). The incidence of behavioral despair in MD group was significant higher than that in C group. There was no significant efficacy of escitalopram on anhedonia and behavioral despair among 3 stressed models. However the recovery incidence from anhedonia (44/140) was significantly lower than that from behavioral despair (76/140) (χ2=14.93, P<0.05). Conclusion The maternal deprivation increases the stress sensitivity and the incidences of anhedonia in adult rats.The efficacy of escitalopram on behavioral despair is higher than that on anhedonia without influence from maternal deprivation. Key words: Maternal deprivation; Chronic unpredictable stress; Anhedonia; Behavioral despair; Escitalopram