Tag Archives: brain

The truth about cats and dogs?

Apropos of what we’ll be discussing for much of next week, this episode of PBS’ Nature series discusses the relationship between humans and our classic domesticated pets – cats and dogs. Through expert interviews, a visit to a Humane Society shelter, and owner-bios reminiscent of the famous couple scenes from When Harry Met Sally, the show seeks to explain – or at least explore – the bonds between pets and their humans.

It’s easy to get indignant about humans domestication of certain animals – we’re asserting our dominance! we’re pretending we rule the globe! we’re stripping them of their natural wild natures! – it’s also important to remember that we evolved alongside our domesticated animals, both pet and pastoral, and through this coevolution we all have become different creatures. Marc Bekoff, a former Guggenheim fellow and Professor Emeritus of Ecology and Evolutionary Biology at UC Boulder who is interviewed extensively in the episode, explains that these bonds of coevolution are strengthened by the presence of mirror neurons in both humans and common pets – that is, dogs and cats. Mirror neurons are what enable us to feel the emotions of another creature, be they of our species or another. As Bekoff puts it, they are “the neural basis for empathy…[required] for the formulation and maintenance of social bonds.” In other words, that prize human emotion – the one that leads to self-awareness, to social structure, to emotional relationships – is, in fact, not human at all.

Now, I’m not saying we shouldn’t point out the often elitist – or at least excessively moral – human paradigm that we, as a species, tend to impose on the rest of the planet’s animals. And it’s important to note that these animals are not human – they are close to us, but they are not, and never will be the same as us. As one of the dog owners interviewed in the opening sequence says, “they’re another tribe…and what I really love about dogs and cats is that they’re not like us.”

So watch the documentary. Though be warned, it might bring you to tears –I know it did me – the kind of hot, messy, gut-wrenching tears that we seem to save for the inevitable goodbyes to our pets.

How Much is Too Much?

I was actually just reading the article written about mice with human brains before I saw Walter’s post on the same article. As carefully justified in the article, and also mentioned by Walter, this kind of research is purely used for medical purposes, and not anything like attempting to create new species. Being able to “try out both stem cell interventions and other potential cures on living human brain cells without having to use humans in the process” is the big advantage, and it’s a big step towards curing many diseases.

What I read from this article is that any kind of research or experiment is okay as long as it stays in the lab. They did manage to ban mating among the artificial species to try to regulate this branch of research. It seemed that they were saying that if we don’t allow reproduction and don’t release them into the wild, creating a mouse with a human brain is perfectly fine. Right now they are only studying brain development through medium that’s not human. But what will happen once they want to study environmental effects on the brain? Would they have to make a creature with a brain so similar to a human’s that it would react the same way a human would when stimulated by its surroundings? If we created an new species that has almost the exact characteristics as humans, is it still going to be morally right to do so if we promise to keep it in the lab?

All these questions lead to the debate of where to draw the line and how much meddling with nature is too much. We allow the sacrifice of many dispensable lives of mice in order to cure humans of illnesses. In the future, when we advance even further in science and medicine, are we just going to re-convince ourselves that whatever research we do then is completely justified by the benefit is brings?

Ethics War

Like Lindsay, our class on chimeras really got me thinking.  This field of genetic experimentation has so much promise… but should the distant goal of miracle cures allow us to do whatever we want with test animals?  Creating a mouse with a functioning, thinking, and feeling human brain would be cruel.  I went on to the nat geo website to learn more about this controversial subject.

In 2005, a mouse with functioning human brain cells was created.  But, only one tenth of one percent of all the mouse’s brain cells were human.  This is not enough to make the mouse have a “human” brain, but it proved that embryonic human stem cells can grow functionally in a foreign environment.  This information is amazing, as it illustrates the amazingly promising versatility of stem cells.  Scientists hope that one day stem cells can be used to cure many degenerative nerve diseases.  In order to prevent ethical debate, they carefully monitor the subject mouse’s brain activity, to make sure that it doesn’t display any “human” brain activity.

But even if a mouse does not have a totally functioning human brain, is it ethical to put even a small amount of human brain cells into a mouse?  Machiavelli would say it is.  But many bioethicists say it is not.  The opposition to this research dubs it “inhumane,” and that it “crosses the natural border.”  Is this overreacting? One researcher states that “A few thousand human brain cells will not turn a house pest into Mickey Mouse.”  Maybe this is true, maybe it isn’t.  I honestly haven’t formed a concrete opinion on this issue yet, because both sides have such valid arguments.  Are we impeding the progress of finding miraculous cures to life-threatening human diseases in defense of mice?  Or are we putting innocent creatures through insufferable pain and defying Nature itself?  There are definitely boundaries to how much science should interfere with the life of an animal, but I think this early brain cell testing is ok for the time being.  The mouse is still a mouse with a mouse brain, just with a few human cells thrown into the stew.  Just like Robin Williams with his new bovine-valve heart is still human, the mouse is still a mouse.  The genetic change in its brain hasn’t changed how it lives (as of now).

Mickey mouse hasn’t been created just yet, and hopefully never will be.  There are many laws setting regulations on research such as this, defining just how “human” you can make an animal.  In Canada, it is forbidden to create a human-animal “chimera.”  Are there loopholes in laws such as these though?  At what point does an animal become “too human?”  Everything is very subjective.  I expect even more debate to emerge in the coming years over this controversial issue.  My advice for the scientists: cure the sick and ailing parents of the bioethicists with the results of your stem cell research.  That should quiet them.  My advice for the bioethicists: Keep a careful eye on those scheming scientists, but actually learn about the research being done before you condemn it.  Come off as educated people, not hippie-nazis.