A brain circuit that governs emotion is passed down from mother to daughter and may be an inherited factor contributing to depression, research has shown.
The structure, known as the corticolimbic system, is less likely to pass from mothers to sons or from fathers to children of either gender, the US study of 35 families found.
Previous work has shown that the risk of depression is strongly associated between mothers and daughters. Animal studies have also suggested that the brains of unborn females are more likely than those of males to be affected by a mother's stress.
Lead scientist Dr Fumiko Hoeft, from the University of California at San Francisco, said: "Many factors play a role in depression - genes that are not inherited from the mother, social environment and life experiences, to name only three. Mother-daughter transmission is just one piece of it.
"But this is the first study to bridge animal and human clinical research and show a possible matrilineal transmission of human corticolimbic circuitry, which has been implicated in depression, by scanning both parents and offspring.
"It opens the door to a whole new avenue of research looking at intergenerational transmission patterns in the human brain."
Dr Hoeft and her team used magnetic resonance imaging (MRI) brain scans to measure grey matter volume in the corticolimbic systems of parents and their offspring in 35 healthy families.
"Grey matter" is the part of the brain composed of the bodies of nerve cells, rather than nerve fibres.
"This gives us a potential new tool to better understand depression and other neuropsychiatric conditions, as most conditions seem to show intergenerational transmission patterns," said Dr Hoeft.
"Anxiety, autism, schizophrenia, dyslexia, you name it - brain patterns inherited from both mothers and fathers have an impact on just about all of them."
The findings are published in the Journal of Neuroscience.
