Have to disagree with the Grey Lady about this (boldface mine):
Scientific research has a gender gap, and not just among humans. In many disciplines, the animals used to study diseases and drugs are overwhelmingly male, which may significantly reduce the reliability of research and lead to drugs that won’t work in half the population.
A new study published in the journal Nature Neuroscience suggests that research done on male animals may not hold up for women. Its authors reported that hypersensitivity to pain works differently in male and female mice. For males, immune cells called microglia appear to be required for pain hypersensitivity, and inhibiting their function also relieves the pain. But in female mice, different cells are involved, and targeting the microglia has no effect. If these differences occur in mice, they may occur in humans too. This means a pain drug targeting microglia might appear to work in male mice, but wouldn’t work on women.
Failure to consider gender in research is very much the norm. According to one analysis of scientific studies that were published in 2009, male animals outnumbered females 5.5 to 1 in neuroscience, 5 to 1 in pharmacology, and 3.7 to 1 in physiology. Only 45 percent of animal studies involving depression or anxiety and only 38 percent involving strokes used females, even though these conditions are more common in women.
There are two problems with this policy. First, in the absence of additional funding, NIH will either have to reduce the overall number of studies (that is, an even lower grant funding rate) or sample sizes will shrink. The latter means that more studies will be spurious artifacts due to small sample sizes.
But the other problem with the editorial is that it shows a misunderstanding of what model systems are. They are called model systems, not mimics for a reason. They exist to help us model (ahem) biological processes. Obviously, you don’t want to pick a completely inappropriate system–and for certain questions using only males (or males at all)–would be inappropriate. But they aren’t supposed to be perfect replicates of humans.
Of course, philosophical objections don’t matter that much: what will cause a lot of grief are the budget realities.
And because I can:
Well, yeah – and sometimes the reason for the gender selection is important. We use male mice preferentially in our studies because we’re looking at heart function. Turns out that female mice have (to put it crudely) a ‘buffering’ system that masks the effect of the genetic manipulations we do to the mice. Male mice tend to show an effect if there is an effect to show. Female mice generally don’t. This may well be important in terms of clinical treatments, but when you’re looking at basic science determination of something (not to mention getting published), you want to be able to see something if something is there. The fact that maintaining model mouse colonies (let alone rat or rabbit or, God help us, dog or pig) is incredibly expensive also plays a big part. Ah, if only we could experiment on humans, eh? I’ve got a little list…