Why are male mice afraid of bananas?

Researchers from McGill University have identified a form of chemical signaling in mice to protect their offspring. The researchers found that proximity to pregnant and lactating mice increased stress hormone levels in males and even reduced their sensitivity to pain.

“The findings have important implications for improving the reliability and reproducibility of experiments involving mice. This is another example of a previously unknown factor in the laboratory that can affect the results of scientific research, “- said Professor Jeffrey Mogil. psychology at McGill University and EP Taylor’s Department of Pain.

According to co-author Sarah Rosen, “it is likely that female mice are signaling to males who may be considering attacking their children that they will vigorously defend them. Stress poses a threat of future fighting.”

“Mice communicate more with each other than we think, just a lot through the smell,” says Tomb. Researchers began looking for an olfactory chemical. Several fragrances have been identified, but one, n-pentylacetate, is excreted in the urine of pregnant and lactating women. female micehas been particularly effective in creating stress in male mice.

“Interestingly, n-pentyl acetate is also responsible for the unique smell of bananas. After a quick trip to the supermarket for banana oil, we were able to confirm that the smell of banana extract strains male mice as much as pregnant women,” said co-author Lucas Lima.

The discovery represents a breakthrough in the science of mammalian social signaling. “There are a number of examples of male-to-female olfactory signal transmission in rodents, but far fewer examples of female-to-male olfactory signal transmission, especially outside of sexual behavior,” says Tomb.

“Olfactory exposure to mice in late pregnancy and lactation causes stress-induced analgesia in male mice,” Sarah Rosen et al. was published in Advances in science.