Gestational stress alters maternal behavior and inflammatory markers in the olfactory bulb of lactating mice.

Inflammatory markers represent important candidates responsible for the altered behavior and physiology observed after stressful experiences. In the maternal brain, the olfactory bulb (OB) is a key constituent of the neural circuit that mediates the reciprocal interaction between mother and infant. This study aimed to investigate the effects of stress during pregnancy on maternal behavior and inflammatory changes in the olfactory bulb of lactating mice. Female Balb/c mice were divided into two groups: control (CT) and restraint stress (RS). Maternal behavior was performed during the first 8 days of life of the offspring. On the 10th day after parturition, corticosterone, gene, and protein expression were assessed. Stress during pregnancy decreased the maternal index at postnatal day 4 and the nuclear factor-κB 1 (NFκB1) gene expression in the OB. Moreover, females from the RS group showed increased interleukin (IL-1β) protein expression. In contrast, stressed females exhibited a decreased tumor necrosis factor (TNF-α) protein expression in the OB. In conclusion, exposure to stress during pregnancy was able to induce specific postnatal effects on maternal behavior and balance of inflammatory mediators in the OB.