The MacArthur and the Mole
Vanderbilt University neuroscientist Kenneth Catania's animal research is done not with ho-hum rats or mice but instead with less-studied (and more exotic) small mammals, focusing on how their unusual sensory systems work. His studies of the star-nosed mole-a tiny, nearly blind, underground-dwelling wetland beast with an odd schnoz-last week earned him a MacArthur Fellowship. More commonly known as the "genius grant," the award will give the 40-year-old Catania $500,000 over the next five years to use as he sees fit. Most likely, that means continuing to research his subjects, which are more than mere curiosities. As alien as the star-nosed mole looks, its brain is helping unlock some of the mysteries of how the human mind is organized.
Where were you when you found out about the MacArthur award?
I got a phone call at work from [Fellows Program Director] Dan Socolow. I thought I was going to be asked to review grants and was thinking, "Wow, do I have the time?" When he told me why he called, I spilled my drink onto my desk and on my pants. Luckily, it was water. I was basically stunned and speechless.
How did you end up working with moles?
I started out as a volunteer working in the small mammal department of the National Zoo while I was an undergraduate [studying zoology], and eventually I was hired for a research position. I was assigned to collect shrews and star-nosed moles, which are these legendary, bizarre animals that many people wondered about but few people had studied or knew much about. I went to Pennsylvania for a brief lesson, and I got sent out with a bunch of traps into the middle of nowhere. It was like snipe hunting. Then in grad school [in neuroscience], it seemed to be an obvious thing to look at sensory systems of that species and others.
What makes this mole so interesting?
For one thing, its nose. It has a sense of touch even though it's a nose-the star part [with its 22 tentacles] is akin to the outside of our nose. But it is the most sensitive touch organ on the planet: It has five times the number of nerve receptors [in an area the size of a fingertip] as an entire human hand.
Why has the mole evolved in this way?
It appears that they're specialized to eat very small things, like insect larvae. If you're going to eat small things, you have to find and eat them quickly to keep up with your metabolism. So they're an extreme in the biological world.
And extremely quick at the dinner table, as well-your lab has shown that they take 230 milliseconds to identify a piece of food as edible and eat it.
Yes-after we published a paper on their feeding habits, I got a call from the Guinness Book of World Records and later got a big certificate showing that they're the fastest eaters in the world. It's not a very scholarly thing, but I think it's still a childhood fantasy to get something into the Guinness Book!
You found that the part of the brain corresponding to the nose is organized in a similar way?
Yes, if you stained the brain [for study], you'd actually see a star. The touch fovea [the most sensitive part of the nose] takes up the most space. The obvious reason is to save neural tissue: You can specialize a very small part in the sensory system to be very high resolution. It has parallels to the visual system in humans and auditory system in bats-the same patterns recur for those high-resolution sensory systems as well. In humans, if the entire eye were as sensitive as the eye's fovea, your head would be the size of a refrigerator.
Any other comparisons?
Well, we can see how these brain maps change in relation to behavior. In humans, you get an expansion of the area of the brain representing the hand if you were a guitar player or a Braille reader. When someone loses a limb, they may still feel as if it's there, and that may be because the brain area [of the missing limb] is being activated by regions that shouldn't be there. It's being invaded by other parts of the brain map.
How does it feel to know that someone anonymously nominated you for the MacArthur grant?
That's one of the most touching things about it. You're always struggling to do good work and don't know what other people think of it. Most people who are trying to do something a little unusual wonder if it's the right thing to be doing.
And what will you do with the money?
One way or another, it will support the studies, though I'm still thinking about what to do. I'll keep studying a range of species-naked mole rats, elephant shrews-as well as the star-nosed mole. One thing might be to do more photography of these species and bring the fascination of these animals to the general public. I also might try to preserve some habitat sites. And I might go in different directions: I am always interested in other mysteries.
This story appears in the October 2, 2006 print edition of U.S. News & World Report.