Researchers at Harvard Medical School found that female lab rats displayed more stable behavior than males despite hormonal cycles, emphasizing the importance of including females as well as males in studies. Work published in the journal current biology.
Neuroscientists analyzed the behavior of mice in an open field study. They found that the hormone cycle had little effect on female behavior. Moreover, behavioral differences among men were even greater than among women.
The brains of mice and humans have much in common in structural organization, so mice are used as model animals to study various diseases. For over 50 years, researchers have used predominantly male mice in their experiments. A 2011 analysis found that men use it five times more often than women.
This practice has led to a poor understanding of the female brain, which has likely contributed to the misdiagnosis of mental and neurological conditions in women, as well as the development of drugs with more side effects for women.
This bias is explained by the fact that fluctuations in hormone levels in female animals and females can complicate studies. The new study showed that the evidence for this view has no scientific justification.
The scientists noted that only a set of laboratory mice were considered in their study, so the results cannot be generalized to other animals without additional testing. However, the findings provide strong evidence for increasing the number of female mice in neuroscience and other sciences.
“This is a very interesting example that the assumptions that affect the way we conduct and develop our science are sometimes just assumptions, and it’s important to test them directly because sometimes they’re not true,” said Dana Levy, lead author of the study.