Of Mice And Men: Study Finds Mice Stressed Out By Male Researchers
Scientists are bewildered when the results of their precisely executed experiments cannot be duplicated. This problem has led to a variety of studies attempting to find out why results are sometimes not duplicated, particularly by other researchers in the field. In this study, performed at McGill University in Montreal, one culprit appears to be the gender of the researcher.
Mice (and rats) are used as research models, partially because they have a short breeding cycle and are easy to keep and feed, but mostly because they share 95 percent of the human genome. For example, mice make perfect subjects for disease experiments because they react similarly to humans, so it is very important that results of experiments using mouse models are accurate.
McGill researchers had observed that their lab mice seemed to react to just their presence in the surroundings, and they wondered whether that might skew results of the experiments. So they formed a research team to took into gender of the experimenter as a possible cause of mouse stress. The mice were exposed to male researchers, female researchers, male t-shirts, and female t-shirts in their environments and their stress responses were measured with each exposure.
Indeed, it was found that the male researchers and their (worn) t-shirts brought on stress responses from the mice equivalent to 'forced stress' responses, such as restraining the mice in a tube for 15 minutes or forcing them to swim for 3 minutes. The female researchers and t-shirts did not bring on any measurable stress response from the mice. Thus, the gender of the researcher was shown to be a significant olfactory factor in mouse stress.
The team observed that all mammals exhibit certain chemosignals, or pheronomes, which alert other mammals to their presense in the enviroment; these are more pronouced in the males of each species, the human male excreting such chemosignals primarily from his armpits, more than the human females.
This study suggests even more reasons for women to go into medical research besides their under-representation, but it should not dash hopes for men! Professor Jeffrey Mogil, senior author of the study published in the journal Nature Methods said that the effects from exposure to the pheronomes diminish over time, so the male experimenter could stay in the room with the experimental animals for awhile before testing.
"At the very least," said Mogil, "published papers should state the gender of the experimenter who performed the behavioral testing."
source: Medical News Today