Zika Virus Inoculation During Pregnancy Impaired Maternal Care and Altered Prolactin and Corticosterone Levels in Rats.

Zika virus (ZIKV) is an Orthoflavivirus known for its teratogenicity and for causing congenital Zika syndrome (CZS) in the offspring, but recent studies suggest a negative impact on maternal brain health and behavior following gestational ZIKV inoculation. This behavior, crucial for the offspring's neurodevelopment, is regulated by the hypothalamic-pituitary-adrenal (HPA) axis and prolactin. This study investigated the effect of gestational ZIKV inoculation on maternal care in Wistar rats and its relationship with prolactin and corticosterone levels. Fifty-six females were inoculated intraperitoneally on gestational day 9 (G9) with ZIKV (28 ZK group) or vehicle (28 CT group). Blood and hypothalamus samples from a set of these animals (n = 16/group) were collected 24 h postpartum to quantify corticosterone and prolactin levels by ELISA. Maternal behavior was evaluated on postnatal days 4 and 8 (n = 12/group). ZK rats demonstrated impaired maternal care compared to CT rats. Furthermore, 24 h postpartum, ZK rats had significantly lower levels of serum and hypothalamic corticosterone, and serum prolactin. The findings suggest that gestational ZIKV inoculation compromises maternal behavior in Wistar rats, concomitant with an alteration in the hormonal profile in the immediate postpartum period. The study is pioneering in demonstrating that ZIKV affects crucial components for the regulation of maternal behavior, reinforcing the need for further research to elucidate the mechanism in the maternal brain and develop targeted therapies.