Mice Become Smarter With Addition of Single Human Gene

By Carl Engelking | September 16, 2014 2:39 pm


In an experiment that could explain the origin of the maniacal mouse in “Pinky and the Brain,” researchers spliced a human brain gene into lab mice, and it made them smarter.

These mice aren’t taking over the world any time soon, but they are certainly adept at getting through mazes. Mice genetically modified to carry a human gene associated with speech and language, called Foxp2, learned how to find a reward in a maze significantly faster than normal mice. While this is good news for the modified mice, the findings also reveal clues about how this particular gene contributes to humans’ unique intellectual abilities.

Boosting Brain Power

This isn’t the first time mice have been the beneficiaries of human brainpower. In 2013, scientists made smarter mice by transplanting human glial cells into the brains of newborn mice.

However in this case, the mice had the gene from conception, and so their brains were more thoroughly “humanized.” Researchers compared groups of 10 to 20 “humanized” mice with the same number of controls in a series of navigation tests. The mice were placed in T-shaped enclosures and were rewarded with chocolate if they made the correct turn at the end. The mice could use two options to help them make the right choice: landmarks visible from the maze, or the texture of the floor (rough turn left, smooth turn right).

When placed in a maze where mice could use both landmarks and floor texture, mice with the human gene performed far better than normal mice. They learned the route in 7 days rather than the 11 days it took normal mice. However, when mice could only use one cue — landmarks or texture — there was no significant performance difference.

So these mice weren’t all that smart? Not so fast.

What’s the Difference?

Researchers set up their experiment to specifically test two types of learning that occur in humans: declarative and procedural. Declarative learning requires conscious effort, like reading directions to a new place. Procedural learning is unconscious, like driving your daily route home. The landmarks in the maze stimulated declarative thinking, while the floor textures stimulated procedural thinking.

Mice with the human gene, researchers say, excelled when both options were present because they were better than normal mice at transitioning between conscious and unconscious thinking. The advantage was muted when only one type of navigational aid was available. They published their findings Monday in Proceedings of the National Academies of Science.

A Key to Learning

This experiment highlighted the important role that Foxp2 plays in human cognitive development. When we learn skills such as a new language or how to play an instrument, we use conscious (declarative) thinking at the start, but with practice these skills become unconscious (procedural) in our minds. Researchers believe the Foxp2 gene is key to making this transition, but how our minds do it is still not fully understood.

The findings highlight how influential a single gene can be on the cognitive abilities of both mice and men. And they underscore another interspecies similarity too: the motivating power of chocolate.


Photo credit: Fer Gregory/Shutterstock

CATEGORIZED UNDER: Mind & Brain, top posts
  • lump1

    This is so ethically interesting! I’m picturing a future in which we might be able to cure many human cognitive disabilities with gene therapy. That’s something that we should do, it’s a moral duty. But what if we discover that the same gene therapy strategies, when scaled up and applied to chimpanzees, could bring their intelligence up to about 50+ IQ equivalent, a level where human rights are indesputable? If we have the duty to treat cognitively disabled humans, does the same apply to chimpanzees? Or dogs, or mice? Sure, chimpanzees are not “naturally” human-level smart, but there is nothing normative about naturalness. The whole point of technology is the sense of duty to *improve on* nature. Why should this duty end at the boundaries of our own species? Isn’t that chauvinistic? It’s almost certainly in the interest of the chimpanzee to have human-level intelligence, just like it’s in the interest of every person…

    • William Carr

      “Operation Uplift” becomes real.

      Dolphins, dogs, and especially cats.

      Cats are already great hunters and added IQ would make them even better.

      There are parts of the world infested with vermin, and super-smart cats would be excellent at dealing with the problem.

      Plus, they’d make better pets.

    • tom

      Its in the chimpanzee’s best interest to have a human’s level of intelligence? What presumptuousness!

      Moral duty to cure? Horseshit.

    • Metalhead Nick

      Okay, first, why do we have a moral obligation to raise the intelligence of the mentally handicapped? I mean this in a philosophical sense. Taking an ‘is’ statement and making it into an ‘ought’ statement is extremely hard to defend. Many philosophers would say impossible. What rationale do you have to make unassailable such a blanket statement. And as to other animals, well ghat does tie into human chauvinism. If we have a sense of some kind of moral imparative, it necissarily arises from being a social species in a human social context. That is why, extremists excluded people value the life of another person more than that of a cat , or dog, or any other animal I can name. There is nothing wrong with that at all. While our moral sentiments can carry over to other species they evolved interpersonally and are far and away more important interpersonally than interspecially. And how exactly is there nothing normative about naturalness? Kinda seems the other way around, but then again, I don’t really like to differentiate between natural and unnatural. The only reason people do is because of our human chauvinism. Setting ourselves apart when we are just products of nature doing what we do naturally.

      • Michael Duke

        “A moral obligation to raise the intelligence of the mentally handicapped?” Maybe not, however, they should be able to take care of themselves and be independent. Not a tax burden…if possible. Hitler murdered the handicapped and aged along with the Jews because they couldn’t contribute to his aspirations. We only have the constition and a thing called ‘the Law that keeps us out of the caves.

        • Metalhead Nick

          Perhaps , but that’s still to taking an “is” (a statement of fact) and draw a “should” conclusion. This is even allowing that there are knowable facts, which is also debatable. Regardless, we humans are the measure of this as well, that was my point. That and that every species gives special attention to it’s own kind. That is fine, natural, and normative.

          I’m confused as to what hitler has to do with anythin. Just because hitler did or did not do something shouldn’t be a moral standard. Hitler used to paint. Does that make painting evil? I’m pretty sure committing genocide is generally about as “evil” as people get, whether or not hitler had existed. But again, it is “evil” as such because people value people more than other species. Natural and normative. And people really still do tend to like other species more than visa versa. I’m pretty sure people care more about lions than they care about us.

          Also pretty sure houses were invented long before the constitution, codified law , etc.

  • Mark Miller

    How can this not be a good idea.

  • Randman

    Are you kidding me? We want smarter mice? For what? So they can figure out how to better rob grain silos? So they can avoid cats and spread disease? This is a really bad idea to put human DNA inside of animals.

  • Canis Lupus

    If we let nature take its course with diseased, starving and mentally stunted Africans, we’d have room on this world for fellow sapient species. Lord knows I’d rather have sapient cats, dogs, raccoons, rats and mice for neighbours than some microcephalic thuggish Somali.


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