‘Use more of female specimens for balanced research findings’

MUMBAI: Researchers should include more female animal specimens in laboratory experiments if they want to avoid skewed results, a study by a three-member team at Tata Institute of Fundamental Research (TIFR) said.

The study, published in International Journal of Stress Management, said female brain responds to stress differently than male brain, and points to how pre-clinical research globally has focussed on male specimens, especially for stress-related disorders such as anxiety and depression, which are higher among women, while substance abuse is observed more in men.

Researchers from TIFR observed that study results are important because there are sexually dimorphic rates among humans for stress-related disorders and substance abuse. Sexual dimorphism is a condition where the two sexes of the same species exhibit different characteristics.

“Though cultural factors do play a key role, we found it different between males and females the way neuronal circuits in the brain process acute stressors,” said Vidita Vaidya, neuroscientist, department of biological sciences, TIFR. “Studying only male brain, therefore, gives only a partial insight. It is a serious problem to keep using the male prototype even for studying disorders such as depression even though the risk is higher among women.”

Experts not connected to the study said the findings were important as the sexes behave differently in similar situations. “This kind of knowledge is key to preventing and treating posttraumatic stress disorder, which is more common in women. Very few researchers compare multiple stressors, especially in both sexes, so it also contributes to a fundamental understanding of traditional models used in animal research,” said Rebecca Shansky, associate professor, department of psychology, Northeastern University, Boston, US.

Shansky, whose laboratory has been studying both sexes since 2011, said, “Many researchers don’t use female animals because they mistakenly believe that circulating ovarian hormones will interfere with their “real” data. The reality is that variability in data from male and females is the same, and that variability in females cannot always be attributed to hormones.”

Many researchers don’t use female models as they mistakenly believe circulating ovarian hormones will interfere with their ‘real’ data REBECCA SHANSKY, associate prof, Northeastern University, Boston