Gestational environmental enrichment in preclinical models of postpartum depression and anxiety: effects in mothers and offspring

The peripartum constitutes a critical window for the development of postpartum depression (PPD) and postpartum anxiety (PPA), disorders with consequences for maternal and offspring health. Gestational environmental enrichment (GEE) may represent a non-pharmacological preventive strategy. This study evaluated its effects on maternal behavior, emotionality, and neuronal activity in mothers, as well as offspring development, using two PPD/PPA preclinical models: maternal separation (MS) and intruder male (IM). Female Wistar rats were housed under standard conditions or GEE throughout gestation. On postpartum day 1 (PD1), the mothers and their offspring were assigned to one of the treatments: control, MS, or IM. Maternal behavior was assessed in the pup retrieval test (PD3), and anxiety-like behavior in the elevated plus maze (PD22). Neuronal activity was quantified by immunohistochemistry for ΔFosB. Offspring developmental milestones (PD3–21) and body weight were also evaluated. GEE improved maternal behavior and reduced anxiety in response to both stress models, accompanied by changes in ΔFosB in medial preoptic area, nucleus accumbens, amygdala and hippocampus. Offspring exhibited differences in body weight and developmental reflexes. Overall, GEE induces long-lasting modulation of maternal behavior and neuronal activity across key circuits, and influences early offspring development, supporting its potential as a non-pharmacological strategy against peripartum mood disorders.