MOTHERHOOD CHANGES BRAIN RESPONSE TO MALE-DERIVED CHEMOSIGNALS IN FEMALE MICE

Motherhood is a period of dramatic changes in the life of females, which adjust their behaviours to ensure the survival and wellbeing of the pups. In mice, already by the end of parturition females modify their social interactions with adult conspecifics and furiously attack unknown adults (particularly males) that approach the nest, what is known as maternal aggression.
There is evidence that maternal aggression is triggered by the detection of male-derived chemostimuli (e.g. darcin or MUP20). Male pheromones have different effects throughout the lifespan of a female mice, eliciting attraction during adulthood and aggression during motherhood, suggesting adaptations in the central processing of these stimuli. This study aims to understand the neural mechanisms underlying these changes occurring during motherhood and how they are related in the shift in female responses to male chemosignals, form attraction to aggression.
For this, we exposed virgin females and dams to clean or male-soiled bedding to analyse their behaviour and processed their brains for cFos immunochemistry to measure neuronal activity in different brain areas. In this way, we are able to combine the analysis of females’ chemoinvestigation and social behaviour with the assessment of the patterns of activity of the sociosexual, motivational and chemosensory (olfactory and vomeronasal) brain networks. Our results suggest that motherhood produces sharp changes in the pattern of male-chemosignals induced brain activation.
Funding sources: Ministerio de Ciencia e Innovación (PID2019-107322GB), Universitat Jaume I (UJIA2019-14; GACUJIMC/2024/23; GACUJIMC/2025/14; 19I004-02).