Postpartum administration of Citalopram reverses gestational stress-induced depressive-like behavior and structural modifications in the reward pathway
Postpartum depression (PPD) is a common complication following childbirth experienced by approximately 20% of new mothers. We have previously shown that chronic gestational stress, a risk factor for PPD, induces depressive-like behavior in postpartum rats and impairs maternal care, a rewarding, motivated behavior. These behavioral consequences of gestational stress are accompanied by structural changes on neurons in the nucleus accumbens (NAc), a key brain region in the reward pathway which is involved in maternal care and which has been implicated in PPD. Here, we extended our previous work in two experiments. First, we examined the effects of gestational stress on other reward-related behaviors known to be altered in mothers with postpartum depression including anhedonia (as assessed with the sucrose preference test) and maternal motivation (as assessed with the conditioned place preference paradigm). Second, because mothers diagnosed with PPD are often prescribed selective serotonin reuptake inhibitors (SSRI) antidepressants to ameliorate mood and other deleterious effects of PPD, we investigated the extent to which the SSRI Citalopram could reverse stress-induced depressive-like behavior and morphological changes in the NAc. Our results show that along with increased depressive-like behavior, postpartum females exposed to chronic stress during pregnancy (from GD7-GD20) exhibited anhedonia, deficits in maternal motivation as well as structural modifications in the NAc. We also found that postpartum administration of Citalopram was able to reverse the depressive-like behavior and the structural modifications in the NAc of gestationally stressed mothers. Overall, our results demonstrate that gestational stress induces numerous behavioral symptoms found in depressed mothers and that depressive-like behavior in gestationally stressed mothers is responsive to antidepressant treatment. In doing so, these results expand the validity of our gestational stress model and suggest that structural plasticity in the NAc pathway may play a critical role in mediating depressive-like behavior in PPD.No embargoAcademic Major: Neuroscienc
