Mothers transmit the sense of fear through certain odours to their babies even before they are born. A team of scientists at the University of Michigan came to this conclusion based on studies involving mice. “During their early days of life pups receive the sense of fear through odours released by their mothers during distress,” the scientists said.
In their study the scientists identified areas of the brain where fear signals settle during the early days of life. This could explain why not all children of distressed mothers experience the same effects. Researchers, led by Dr. Jacek Debiec of U-M Medical School, got female rats to associate fear with the smell of peppermint by administering mild electric shocks while they smelled the aroma. They observed that the pups of these mice shrank fearfully from the odour of peppermint even when not accompanied by the shocks. A similar test on pups born to a group of mice that did not fear the smell, showed no such response. Said Dr. Debiec, “In its early days, an infant rat is immune to learning information about environmental dangers unless the source of the threat information is their mother.”
The team focused on a brain structure called the lateral amygdala, an area of the brain where threats are detected and dealt with. When the researchers put the baby rats on a substance that blocked amygdala activity, the pups failed to learn the fear of peppermint from their mothers. They may have, therefore, found a way to stop children from inheriting harmful fear responses from their mothers—a significant breakthrough because medical science has proved that emotional trauma is transmitted down generations.