The dynamic serotonin system of the maternal brain

Abstract

Many pregnant and postpartum women worldwide suffer from high anxiety and/or depression, which can have detrimental effects on maternal and infant well-being. The first-line pharmacotherapies for prepartum and postpartum affective disorders continue to be the selective serotonin reuptake inhibitors (SSRIs), despite the lack of large well-controlled studies demonstrating their efficacy in reproducing women and the potential for fetal/neonatal exposure to the drugs. Prepartum or postpartum use of SSRIs or other drugs that modulate the brain's serotonin system is also troubling because very little is known about the typical, let alone the atypical, changes that occur in the female central serotonin system across reproduction. We do know from a handful of studies of women and female laboratory rodents that numerous aspects of the central serotonin system are naturally dynamic across reproduction and are also affected by pregnancy stress (a major predisposing factor for maternal psychopathology). Thus, it should not be assumed that the maternal central serotonin system being targeted by SSRIs is identical to non-parous females or males. More information about the normative and stress-derailed changes in the maternal central serotonin system is essential for understanding how serotonin is involved in the etiology of, and the best use of SSRIs for potentially treating, affective disorders in the pregnant and postpartum populations.

Serotonin and motherhood: From molecules to mood

“…Ten to twenty percent of women experience anxiety or depressive disorders during pregnancy and the postpartum period, with up to 10% of pregnant and postpartum women in the U.S., Canada, and a number of other countries being prescribed SSRIs [26; 27; 28; 29; 30; 31]. Unfortunately, we know very little about how the serotonergic system is altered during female reproduction and how maternal mental illness can alter these normative changes [32]. Therefore, the main aims of this review are to detail: 1) how the serotonin system of the female brain changes during pregnancy and postpartum, 2) the role of the central serotonergic system in maternal behaviors, 3) how the central serotonin system and SSRIs are involved in maternal mental illness.…”

Depression‐related disturbances in rat maternal behaviour are associated with altered monoamine levels within mesocorticolimbic structures

“…Significantly, these cognitive and motivational processes affected by depression, including attention, behavioural flexibility, decision‐making and effort‐related processes, are key to parenting . In parallel, compelling evidence indicates that the mesocorticolimbic monoamine systems facilitate early aspects of mother‐infant attachment, social memory, and motivation in rats and humans . Interference with dopaminergic, noradrenergic and/or serotonergic signalling severely impacts the onset and early expression of maternal behaviour .…”

“…20,21 In parallel, compelling evidence indicates that the mesocorticolimbic monoamine systems facilitate early aspects of mother-infant attachment, social memory, and motivation in rats and humans. [22][23][24][25][26] Interference with dopaminergic, noradrenergic and/or serotonergic signalling severely impacts the onset and early expression of maternal behaviour. 23,[26][27][28][29][30][31][32][33][34] However, little is known about whether (and how) these monoaminergic systems change throughout the postpartum period to support parenting.…”

Dorsal raphe oxytocin receptors regulate the neurobehavioral consequences of social touch

“…Experimental manipulations that enhance central serotonergic activity increase sociality and affect 19–21 , while manipulations that blunt serotonergic activity decrease sociality and affect 21–23 . Serotonin is also likely involved in the many neuroplastic changes occurring across pregnancy and lactation that are required for motherhood 24,25 . The DR has rarely been studied as a target of oxytocin’s effects on prosocial behaviors (or any other behaviors), despite the fact that the DR has long been known to express oxytocin receptors (OTRs) 26,27 .…”