Tag Archives: science

Mice: Songbirds With Paws

May 6, 2009 By in Science Tags: , , 2 Comments

We romanticize the calls of birds and whales and ascribe meaning to the vocalizations of our pets. Yet most people don’t know that mice talk too, and that we would be wise to listen.

Mice vocalize at ultrasonic frequencies, above the threshold of human hearing. With special audio equipment, it is possible to hear what they would sound like if their vocalizations were brought down to an audible range. Here are two samples of mouse vocalizations, one chirpy and one whistle-like.

Scientists have found that male mice ‘sing’ to potential mates. These vocalizations are composed of syllables that form repeated phrases, a characteristic of song across species. Can you imagine these little guys singing love ballads on your kitchen floor?

The fact that mice vocalize and that these vocalizations are behaviorally relevant is not just fodder for trivia night. It may actually help us understand the causes of major psychiatric and neurological illnesses in humans.

Transgenic (a.k.a. mutant) mice are in widespread use in labs around the globe. Each strain of mutant mouse is designed with a specific change to their DNA. For example, the deletion of a specific gene from a strain’s DNA results in “knockout” mutant mice. By making the gene disappear and seeing what happens to the mice, we learn what that gene does. If the gene is related to disease in humans, we learn something about the disease. This method works more often than you might think, since more than 90 percent of the mouse genome is shared with humans.

Thank god for the remaining 10 percent. Shared DNA aside, we all know that mice and humans are very different, so it can be hard for scientists to tell whether abnormalities in the mouse are truly analogous to symptoms of human disease.

The problem is even tougher in studies of brain function and illness. How can we tell what a mouse does and doesn’t remember? Can mice have symptoms of schizophrenia, depression, or autism? Do they ever feel insecure and yearn for someone to love? Scientists have to put a lot of thought into answering questions like these.

I once attended a talk by Jacqueline Crawley, a neuroscientist at NIMH who wrote the book What’s Wrong With My Mouse? She pointed out that mouse vocalizations might serve as a model for human vocalizations. And since speech and social interaction are affected in several brain disorders, ‘listening’ to mutant mice could help us learn about the genes involved.

Crawley recently published an example of this kind of work: a study of vocalizations in a mutant mouse model of autism. Children with autism usually exhibit abnormal speech and social development. Crawley found that the vocalizations of the mutant mice were also abnormal. Kazow!

It’s too early to draw any real conclusions from this study, or to say that mouse vocalizations are truly analogous to human vocalizations. I’m sure more studies are in the works to find out.

In the meantime, let’s all do our part. If you find a mouse in your home, don’t just kill it. Wait and hear what it has to say.

Modern Relics

May 1, 2009 By in Science Tags: , , , 1 Comment

For millennia, Christians have saved the corpses of saints. Worshipers would make pilgrimages to view the bodies or body parts on display and share in their holiness.

I recently listened to an NPR book tour podcast featuring Peter Manseau, author of a recent book about holy relics. He described how worshipers would be so overcome with awe that a few bit off pieces of the saints’ bodies (in one case, a toe). I was both horrified and impressed. I’ve never believed in anything strongly enough to make me want to go Mike Tyson on the dead.

The relic discussion got me thinking about the modern era, and I realized that science is teeming with relics as well. This is true both on a general and an individual level. On a general level, we can point to archaeologists unearthing ancient remains of lost civilizations and species. A recent Nova special on Neanderthals documented the genomic analysis of Neanderthal remains to answer questions about our common ancestry. More commonly, bones are carbon-dated and skeletons are modeled for their aerodynamics or for bipedal versus quadrupedal motion.

But the most fascinating kinds of modern relics come from specific individuals. They are prized for the unusual features of that individual rather than their representativeness of a species as a whole. For example, Einstein’s brain was preserved and studied. Scientists found that the size and surface morphology of his parietal lobes were different from those in non-genius controls. Fragments of Beethoven’s skull and hair have revealed that the composer died of lead poisoning, which might account for his medical problems later in life, although probably not his deafness. And scientists have been trying to get a DNA sample from Lincoln’s tomb to conduct genetic testing for a specific type of genetic illness, spinocerebellar ataxia type 5.

To understand why relics have persisted over time, it’s useful to ask what purpose they serve. Why collect the dead? As I mentioned, the ancient relics were valuable for their holiness. At the time, religion was the only path to understanding the world. Why are we here? What came before us? How can we gain control of our lives, both on Earth and after death? God was the source of those answers and the relics were a portal to god.

Despite all that has changed about our society and our ways of thinking, modern relics serve the same purpose. They may not be thought of as a phone line to god, yet we still value them for what they can explain. They tell us about our evolution and about the lives of the historical figures who shaped society and have become our modern legends. They provide a window into the nature of human genius, creativity, good and evil; a portal to ourselves. And that is something I can truly believe in.