Gestational stress induces persistent depressive-like behavior and structural modifications within the postpartum...

Area of Science:

• Neuroscience
• Reproductive Biology
• Psychiatry

Background:

• Postpartum depression (PPD) affects one in five new mothers, with pregnancy stress increasing vulnerability.
• Gestational stress in rats increases depressive-like behavior postpartum, suggesting it as a translational risk factor for PPD.
• The nucleus accumbens (NAc) is a key brain region implicated in the neurobiology of PPD.

Purpose of the Study:

• To investigate the effects of gestational stress on depressive-like behavior in early/mid and late postpartum rats.
• To evaluate if gestational stress alters structural plasticity in the nucleus accumbens (NAc) during the postpartum period.

Main Methods:

• Rats experienced restraint stress during pregnancy.
• Depressive-like behavior was assessed using the forced swim test at postpartum days 8 and 22.
• Structural plasticity in the NAc (shell and core) was analyzed, focusing on dendritic length, branching, and spine density.

Main Results:

• Gestational stress increased depressive-like behavior at both early/mid and late postpartum timepoints.
• Stress reduced dendritic length, branching, and spine density in the NAc shell, particularly in early/mid postpartum females.
• The NAc core showed reduced spine density and dendritic length in late postpartum females, irrespective of gestational stress.

Conclusions:

• Gestational stress contributes to postpartum depressive-like behavior in rats.
• Compromised structural plasticity in the NAc is associated with stress-induced postpartum depressive-like behavior.
• These findings offer insights into the neural mechanisms underlying PPD and highlight the NAc's role.