Scientists studying microglia, the brain’s immune cells, find stark gender differences

When comparing microglia—the security guard-like immune cells that are responsible for keeping your brain’s health in check—researchers found strong evidence that it’s time to start studying both sexes equally: “Sex differences in brain structure and function are of substantial scientific interest because of sex-related susceptibility to psychiatric and neurological disorders,” the authors of the study published in Cell Reports wrote.

Researchers were surprised to find such stark differences between the microglia in different sexes. And since men are studied much more often than women, it’s clearer than ever that female participants desperately need to be included, too. (Women are often underrepresented as study participants—they make up only a third of cardiovascular clinical trial subjects, for example—although progress has been made since 1993, when federal agencies mandated that women be included in all US-funded research.)

One-sided research not only creates gender biases with treatment protocols—as in, different people responding differently to the same medication—but it also affects how doctors assume different diseases will present in patients.

“The differences are there, but are not yet sufficiently taken into account when treating patients.” —Susanne Wolf, PhD

And that’s not all: “Sex-specific differences can also be seen in the frequency of neurological disorders,” said lead study author Susanne Wolf, PhD, in a press release, who notes autism is four times more common in boys than girls, while twice as many women have multiple sclerosis than men. “The differences are there, but are not yet sufficiently taken into account when treating patients.” Luckily, Wolf thinks her findings can help the science world move toward more gender equality in studies.

Here are five facts about gender equality Emma Watson wants you to know. Or, find out how Reese Witherspoon is helping close the gender pay gap in Hollywood.