Female rats are not more variable than male rats: a meta-analysis of neuroscience studies
Authors: Becker, JB, Prendergast, BJ, and Liang, JW.
There is considerable concern among researchers that including female animals in preclinical research will increase costs, and variability in the data collected. However, in 2015, Dr. Janine Clayton of the NIH Office of Women’s Health Research observed, “Understancing scientific findings in the context of sex – be they similarities, differences, and/or complex nuances – is crucial for correctly applying research-derived knowledge toward achieving ultimate objectives.”
These authors from Michigan, Chicago, and New York performed a large (311 articles) meta-analysis, studying research over 4 years, and measuring diverse aspects of brain function. They investigated whether female rats are more variable than male rats in neuroscience-related traits. Across all traits, no sex differences were found in trait variability. And female rats were no more variable at any stage of the estrous cycle.
This information should begin to allay concerns about eliminating female rats from neuroscientific animal studies, and add to our data that is sorely lacking on sex and gender differences. We look forward to future similar studies in other areas of study.