OXYTOCIN BRAIN SIGNALLING AND MOTIVATED MATERNAL BEHAVIOURS IN RATS: CHANGES IN SOCIO-SEXUAL AND MOTIVATIONAL BRAIN REGIONS

Motherhood is characterized by pronounced brain plasticity and behavioural adaptations that promote offspring survival and, ultimately, reproductive success. These changes are driven by hormones and nonapeptides acting on the brain throughout pregnancy, parturition, and lactation, as well as by external stimuli derived from pups. During the maternal period, brain regions belonging to the socio-sexual and motivational networks are particularly sensitive to this neurochemical modulation. In this context, the oxytocin system plays a central role in the development and expression of maternal behaviours, including pup care and defensive aggression towards potential intruders, thereby constituting a key modulator of social and maternal behaviour. However, the specific neural targets of oxytocin signalling and its precise contribution to maternal motivation remain only partially understood. In the present study, we aim to investigate oxytocin receptor distribution within socio-sexual and motivational brain regions and its relationship with maternal behaviour in Sprague–Dawley female rats. To this end, we assessed maternal behaviour and oxytocin receptor expression, using autoradiography, in several brain regions of females under different conditions designed to disentangle hormonal/nonapeptidergic influences from pup-derived experience: pup-naïve virgins, pup-experienced virgins, dams, and dams housed with pup-experienced virgins. Together, these findings provide new insights into the role of the oxytocin system in motivated maternal behaviours and its contribution to the functional modulation of specific socio-sexual and motivational brain regions in the context of motherhood.
Funding sources: Universitat Jaume I (UJIA2019-14, GACUJIMC/2024/23 GACUJIMC/2025/14), Ministerio de Ciencia e Innovación (PID2019-107322GB), Generalitat Valenciana (GV/2020/173, ACIF/2021/330) and German Research Foundation (DFG BO 1958/8-2).