Scientists find clue to ‘maternal instinct’

“Many researchers have attempted to investigate the difference between the oxytocin system in females versus males, but no one has successfully found conclusive evidence until now. Our discovery was a big surprise,” said Ryoichi Teruyama, LSU Department of Biological Sciences associate professor, who led this study published in PLOS ONE.

The oxytocin receptor cells are present in the brain area thought to be involved in the regulation of maternal behaviour. Moreover, the expression of oxytocin receptors in these cells are only present when estrogen is also present. These imply that these cells are involved in inducing maternal behaviour. In addition, it confirms what many recent human studies have shown: there is a connection between an altered expression of oxytocin receptors and postpartum depression.

Postpartum depression contributes to poor maternal health and has negative effects on a child’s development. A number of studies have found that children of depressed mothers are at risk for a wide range of cognitive, emotional, behavioural and medical problems. Therefore, postpartum depression is a major public health concern that has significant adverse effects on both mother and child. About 10 to 20 per cent of women experience postpartum depression after childbirth.

This new discovery that occurred at LSU opens doors to potential new treatments and drugs for postpartum depression targeting oxytocin receptor cells.

“I think our discovery could be universal to all mammals that exhibit maternal behaviour, including humans,” Teruyama said.

Source: Louisiana State University

Reference: Kaustubh Sharma, Ryan LeBlanc, Masudul Haque, Katsuhiko Nishimori, Madigan M. Reid, Ryoichi Teruyama. Sexually dimorphic oxytocin receptor-expressing neurons in the preoptic area of the mouse brain. PLOS ONE, 2019; 14 (7): e0219784 DOI: 10.1371/journal.pone.0219784