Mother rats literally groom their daughters to be attentive or neglectful mothers themselves, concludes a team of neuroscientists at McGill University in Montreal.
Adult females who were frequently licked and groomed by their mothers behave similarly toward pups in their care. They also show heightened sensitivity to the hormone estrogen in brain regions devoted to maternal behavior, say Michael J. Meaney and his colleagues. This physiological effect of grooming suggests that a change in the female pup's brain governs the animal's own mothering styles, the team concludes in the Oct. 23 Proceedings of the National Academy of Sciences.
In contrast, Meaney's group finds that adult females who were rarely licked and groomed by their mothers mirror that minimalist maternal style and exhibit relatively little estrogen sensitivity in mothering-related brain regions.