Science and technology: Neuroscience: Brain mater
Scanning reveals what pregnancy does to a mother’s brain.
As any parent will tell you, once you have had children nothing is ever quite the same.
Including, it seems, their mothers’ brains.
In a paper just published in Nature Neuroscience, a team led by Elseline Hoekzema of the Universitat Autonoma de Barcelona, in Spain,
describe for the first time how pregnancy alters women’s brains, rewiring them in ways that persist long after a child has been born.
Dr Hoekzema and her colleagues performed detailed brain scans on 65 female volunteers, none of whom had been pregnant before, but hoped to be in the near future, and a further 20 who had no such desire.
About 15 months later, by which time 25 of their volunteers had carried babies to term, they repeated the process.
Comparing the scans showed significant reductions in the volume of grey matter in the brains of the new mothers.
(Grey matter contains the main bodies of nerve cells; white matter, the brain’s other component, consists mostly of the nerve fibresthat link those cells together.)
The effect was reliable enough that it could be used by itself to predict, with perfect accuracy, which of the women had been pregnant and which had not.
And it was persistent, too. When the researchers retested the mothers two years later, most of the alterations were still present.
DrHoekzema and her colleagues suspected that something in the biological process of pregnancy itself was causing the changes.
To double-check, and to make sure that the experience of preparing for parenthood was not the true culprit, they also compared their women’s brains with those of some men—both fathers and those without children.
The men’s brains, like those of the childless women, showed no such pattern of changes.
And the results fit with studies on animals.
Rats that have had pups, for instance, show notable and lasting changes in brain structure.
They also tend to be less anxious, better able to cope with stress, and to have better memory than their pupless contemporaries.