Good mothering changes the brain

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Good mothering changes the brain

July 1, 2004
Nature Research journals
and World Science Staff

Among rats, good mothering changes the brain in a way that improves stress response, researchers have found. That in turn improves the offspring's parenting skills as an adult.

In times of stress, the brain releases hormones that give rise to instinctive stress responses. These responses may serve us well during crises, but over the long term, the brain needs a mechanism for keeping these hormone levels under control.

A new paper in the August issue of the research journal Nature Neuroscience explains how physical attention from the mother can change the way that rats' brains deal with stress for the rest of their lives.

Michael Meaney and colleagues at McGill University in Montreal previously found that baby rats whose mothers spend a lot of time licking and grooming them grow up to be less fearful, more well-adjusted adults, who in turn give their own babies the same kind of care.
While a baby rat is being licked and groomed, the brain temporarily boosts activity of a gene that makes molecules known as glucocorticoid receptors in a region of the brain called the hippocampus. This region is part of a feedback system that the brain uses to keep stress hormone levels under control.
In the new study, the authors found that physical mothering also causes long-term changes in the gene itself, leading to tighter control over stress levels for life. These findings demonstrate one striking consequence of the parental environment on brain development, permanently shaping the activity of a gene controlling the brain's stress responses.