Breastfeeding babies triggers a surge of ‘trust’ hormone in mothers

BABIES who are breastfeeding trigger a surge of a “trust” hormone in their mothers’ brains, scientists said.

Researchers have for the first time been able to show exactly how a baby feeding from its mother’s breast causes a wave of the hormone oxytocin to be released.

The hormone has long been known to cause milk to be let down from the mammary glands, but it is also involved in the enhancement of trust and love in humans and animals.

However, large, regular pulses of oxytocin are needed to create the wave released when a mother breastfeeds, strengthening the bond between mother and child.

Now experimental neuroscientists and theoreticians from the University of Warwick, working with scientists across Europe, have found a likely answer to how the few thousand neurones, which are specialised to release oxytocin, are marshalled together to create the wave.

They discovered that in response to suckling the neurons start releasing oxytocin from their dendrites – a branched part of the cell — as well as from their nerve endings.

The finding was unexpected because the dendrite is usually thought of as the part of a neurone which receives, rather than transmits information.

The release of oxytocin from the dendrites allows a massive increase in communication between the neurons, co-ordinating a “swarm” of oxytocin factories which produce intense bursts of oxytocin, released at five-minute intervals.

The activation of the oxytocin-producing neurons is an example of an “emergent process”, scientists said, explaining it as a closely co-ordinated action developing without a single leader, in the same as a flock of birds or insects swarms.

University of Warwick computational biology researcher Professor Jianfeng Feng said: “We knew that these pulses arise because, during suckling, oxytocin neurons fire together in dramatic synchronised bursts.

“But exactly how these bursts arise has been a major problem that has until now eluded explanation.

“The model gives us a possible explanation of an important event in the brain that could be used to study and explain many other similar brain activities.”