Gene "Lets Infants Bond With Mother"

A single gene may play a key role in determining whether infants bond with their mothers, say scientists. Tests on mice have found that knocking out the gene can transform the way newborn mice relate to their mothers. The gene regulates a receptor in the brain that responds to opioids, ranging from painkillers to heroin. Writing in the journal Science, researchers said it also enables infants to find mums "rewarding" and bond with them.