Researchers at the Francis Crick Institute found that pregnancy hormones can change a mouse's brain to get ready for motherhood.
They discovered that estrogen and progesterone affect a small group of brain cells and make them better at taking care of babies, even before the babies are born.
Let's find out more about the research to understand whether it's relevant for people too.
What they have discovered
Usually, mice without babies don't pay much attention to baby mice, but moms take care of their babies all the time.
Scientists used to think that the hormones during birth were the most important for this mom behavior.
But they noticed that even mice that didn't give birth but got pregnancy hormones, or mice that had C-sections, acted like moms.
How it works
In this new study, they found that pregnant mice started acting more like moms in late pregnancy, even without seeing baby mice.
These special brain cells, called galanin-expressing neurons, in a part of the brain called the medial preoptic area, were affected by estrogen and progesterone.
These hormones made the neurons less active and more responsive.
Taking away the hormones stopped the mom behavior, showing that they're crucial during pregnancy.
Some changes in the brain lasted a month after giving birth, and some seemed permanent, suggesting pregnancy can change the female brain for a long time.
The researchers think this brain rewiring might happen in pregnant humans too, alongside other factors like environment and social cues, to affect how moms behave with their babies.
