The trouble with lab mice

You've probably seen this caveat pretty often: Just because a study that uses mice as subjects produces a specific result, doesn't mean you'd get the same result using human subjects. Mice are handy research animals, but they aren't perfect analogues to humans. A mouse study is a stepping stone towards better evidence. It is something we do because there are potentially useful ideas that we should not try out on humans first. But mouse studies should not count as incontrovertible proof of anything.

Usually, when that caveat comes up, the person giving it is talking about fundamental differences between mouse biology and human biology. For instance, a mouse might only need one copy of a genetic factor to grow normally. Meanwhile, a human needs to have both copies or risk altered sexual development.

But there are other problems with mice, problems that have more to do with how we select, breed, and raise mouse models. In a fascinating three-part series on, Daniel Engber looks at how we undermine the usefulness of our own lab mice, and the risks we take when we do so.

If you put a rat on a limited feeding schedule—depriving it of food every other day—and then blocked off one of its cerebral arteries to induce a stroke, its brain damage would be greatly reduced. The same held for mice that had been engineered to develop something like Parkinson's disease: Take away their food, and their brains stayed healthier.

But Mattson wasn't so quick to prescribe his stern feeding schedule to the crowd in Atlanta. He had faith in his research on diet and the brain but was beginning to realize that it suffered from a major complication. It might well be the case that a mouse can be starved into good health—that a deprived and skinny brain is more robust than one that's well-fed. But there was another way to look at the data. Maybe it's not that limiting a mouse's food intake makes it healthy, he thought; it could be that not limiting a mouse's food makes it sick. Mattson's control animals—the rodents that were supposed to yield a normal response to stroke and Parkinson's—might have been overweight, and that would mean his baseline data were skewed.

Part 1: The unhealthy lives of industrialized lab mice
Part 2: The trouble with focusing so much research on one single mouse species
Part 3: Why the naked mole rat (and the Burmese python) can help


  1. But mouse studies should not count as incontrovertible proof of anything.

    The scary bit is that this would apply to the null results, too.

    How many life-saving treatments for humans are discarded because they don’t help in mice?

  2. Labs that experiment on animals are gulags of  unimaginable suffering, hells on earth, a heartbreaking, silent holocaust.

    1. I collaborate a lot with the vet school at my university in terms of using animals as human models, but I’m part of a pediatrics research group – do I take samples from PICU/NICU instead? Genuinely interested in the alternatives. 

  3. Yay Maggie — as always, good science coverage!  One thing I didn’t see was a discussion of the fact that even “standardised” mouse species (e.g. Black-6) are not all the same, as populations have diverged (evolved) by being bred for hundreds of generations in separate facilities.  A UK and a US mouse of the same strain are not actually the same.  This is important because studies need to be reproducible: people need to be able to re-run the experiment to check they get the same results.

    I work with a group that does “wet lab” cardiac research, and uses the data to create computer models.  One problem we’ve noticed is that, even when authors think they’re writing everything down, they’ve missed really important information — such as the strain of mouse (what is “wild type,” exactly?), or the tempearature or solution for the cells in the experiment.  This means that the resultant computer models are basically frankenstein creations bolted together with whatever information we can scrounge from various publications.  It’s becoming enough of a problem that we’ve just published a paper on Minimum Information Standards for our field.

    The paper is meant to be open-source and freely available, but we’re still waiting for the payment to go through (sigh) so it’s stuck behind a paywall for the next couple of weeks.  But once it’s available, you can see our example, where we took one of our own papers, and noted whether we’d included all the information in our new MICEE standard in that paper.  We hadn’t! (if you want to see the Minimum Information Standard paper now, please contact

  4. As soon as one of you rocket scientists come up with a better model for research, please let us scientists know. Model organisms are a huge part of biological research, and without them we’d be no where near where we are today. Careful where you point that thing.

    I’d also like to point out to the gulag comment, that there are several layers of checks you must go through for any sort of animal research. I’d encourage you to understand the status quo. These are not the days of “Unnecessary Fuss” where you have people slamming baboons wearing crash helmets into walls. I would say, if you believe in what you really believe in, put your money where your mouth is and join IACUC:

    These people are the real defenders of animal rights, as they are a very real force to be reckoned with in laboratories. I have seen entire labs been shut down, and then subsequently gone under at universities.  They are where the wheels hit the ground for animal research.

  5. Spoonage–thank you.  I hate discussions of animal testing that inevitably go to the New Godwin for the subject:  “Think of the micey-wiceys!!” and “Test on people/condemned criminals/volunteers” (yeah, because doing a double-blind for a rare form of brain cancer is SO much easier on humans, ethics aside, than using genetically-manipulated mice specially bred for that purpose). 

    Quick, PETA, in 25 words or less, explain tertiary genetically-influenced RNA path mechanisms and how they relate to certain kinds of cancer!  Then in another 25 tell me how you’re going to do Phase Zero testing without an animal (usually mouse) model.

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