London, July 7 : If mums want to experience a natural 'high' then all they need to do is take a look at their baby's smile, say researchers.
According to boffins, the sight of their baby smiling works by triggering 'feel-good' part of the brain that deals with sensations of reward and pleasure.
As a part of the study, researchers from Texas Children's Hospital 28 first-time mums, with babies between the ages of five to ten months, to the test.
The mothers underwent a MRI brain scan while looking at pictures of their own babies and also other infants.
Researchers noted that when the mums looked at the infants' faces, the scanner showed the flow of blood in their brains and revealed the regions that were the most active at any time.
What was interesting was that as soon as the mothers identified their own baby, the areas of the brain associated with 'reward' went on alert and the brain chemical dopamine, important for learning, motivating, sleeping and controlling movement, became active.
The strength of the reaction depended on the babies' expression, with a smiling face triggering the biggest reaction, reports the Telegraph.
Lead author of the study Dr Lane Strathearn said: "These are the areas that have been activated in other experiments associated with the neurotransmitter dopamine.
"It may be that seeing your own baby's smiling face is like a natural high," he added.
The findings are published in the American medical journal Pediatrics.