The brains of new mothers release a "trust" hormone triggered by their babies breastfeeding, scientists have 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 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, published in the journal PLoS Computational Biology, was unexpected because the dendrite is usually thought of as the part of a neurone which receives, rather than transmits, information.
University of Warwick computational biology researcher Professor Jianfeng Feng said: "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."