March 7, 2008

Did you know that your brain benefits from a workout, just like your body does? You can exercise your brain by doing crosswords, playing cards, and learning about new things. Exercise your brain today by learning more about Utah Brain Awareness Week, March 10-16, 2008. For more information about your brain and Brain Awareness Week, check out these websites:

• The New Science of Addiction: Genetics and the Brain, from Learn.Genetics.utah.edu at The University of Utah
• The Dana Foundation
• Brain Awareness Week at the Society for Neuroscience

Feed that brain!

The brain makes up just two percent of our body weight, yet it consumes 20 percent of the energy we use each day. Students from The University of Utah and Brigham Young University are taking this message to Utah schools during Brain Awareness Week.

When neuroscience graduate students at The University of Utah are not sharing their brains with schools, they have important day jobs. They are scientists who perform independent research to answer important questions about how the brain and nervous system work. Most use "model organisms" in their research – animals that share many genetic and biological similarities with humans.

I's hard to believe that a tiny worm or a fruit fly can tell us so much about how human brains work. But it's true! Read on to learn how scientists use model organisms in their brain research.

Mouse

Researchers can change mouse DNA by deleting specific genes or adding new ones. In fact, University of Utah profesor Mario Capecchi won the Nobel Prize in 2007 for inventing this technique! Mice mature and breed quickly, so the effects of these changes can be seen very soon – much more quickly than if researchers used more complex animals. Because mice grow so fast, scientists can also see how the mouse grows, how their organ system forms, and how their central nervous system develops.

Mice and humans share many of the same genes, so we can learn a lot about human disease by studying mouse strains that have similar disorders. Imagine doing an experiment on more complex animals and having to wait 18 years or so to get your results! Working with mice is a much faster way to answer biological questions.

Worms

Pull out an eyelash. Now imagine a tiny see-through worm that’s about half as thick and about 100 times shorter. They normally live in soil, so if you have potted plants at home, you probably have some of these critters around. These tiny worms are helping scientists explain all kinds of things about how life works – even things as complicated as human brains!

Despite having only 949 cells, this worm, called Caenorhabditis elegans (pronounced “SEE-noh-rab-dye-tis ELL-uh-ganz”) is able to sense and respond to all kinds of signals from their environment. What’s more, they learn from these signals and decide were food is most likely available.

But how will learning about how a tiny worm behaves help us understand human brains? It turns out that what we learn from can be directly applied to studies of flies, mice, and even humans. This is because the genes that make a worm’s brain are the same genes that make the much more complex human brain. We simply have more nerve cells - we have hundreds of billions, but the worm only has 302.

Figuring out how 302 neurons interact with each other is a lot easier than understanding how the billions of neurons in a human brain work together. And the worm, being so small, is easy to keep and cheap to feed. This means that we can easily do lots of experiments to understand the worm brain. In doing so, we will have come a long way in understanding what makes humans think and feel and learning to help people with brain disorders.

Find out more about worms as model organisms:

• Worm movies
• Photo and video gallery

Zebrafish

Zebrafish is an excellent model for studying brain and spinal cord development. They mature and breed quickly, and the embryos are see-through. Since zebrafish and human brains develop somewhat similarly, scientists can use zebrafish to study human brain disorders.

Fruit Fly

It's amazing how much scientists can learn about humans and our disease by studying animals that look completely different from us! One of these animals is the fruit fly, Drosophila melanogaster (pronounced “dro-SAW-fill-uh meh-LAN-oh-gas-tur). This three-millimeter-long insect has been studied by biologists for almost100 years. We share many of our genes with fruit flies and other insects. Fruit flies can even be used to study human diseases!

Find out more about fruit flies as model organisms:

• Introduction to Drosophila
• Mutant Fly Exploratorium

Chickens

By studying chickens, scientists have discovered a lot about how regions of the brain form, how brain cells connect, how arms and legs form, and how the cells that capture light in our eyes, called photoreceptors, grow.

Since chickens grow in eggs rather than inside their mothers' bodies, scientists can easily do experiments with growing chick embryos. By removing a small piece of the egg's shell, scientists can add drugs or other agents to test how they affect the chick embryo’s development. They can even perform miniature surgeries on the developing chicken while it’s in the egg.

Sparrows

Scientists study singing sparrows and other songbirds to learn about human speech and language. Baby songbirds learn songs just like human children learn to speak. A baby growing up in China will probably learn to speak Chinese before learning any other language, while a baby growing up in France will learn to speak French. In the same way, birds learn different versions of songs depending on where they are raised. These versions are called "dialects." Scientists study the behavior and brains of songbirds that sing different dialects in order to understand how human brains learn different languages.

University of Utah scientists are studying the white-crowned sparrow. This bird travels south in the winter, but in the summer it makes its home all along the west coast of the United States and in the Wasatch Mountains of Utah.

White-crowned sparrows are beautiful bird recognizable by the white stripes on their heads. They sing a song that you might recognize!

Find out more about sparrows and songbirds:

• See pictures and listen to the white-crowned sparrow’s song
• The Life of Birds, by David Attenborough (PBS)

Additional resources

• Kids for Research
• Neuroscience for Kids
• Learn.Genetics.utah.edu, fromThe University of Utah
• Kids Genetics

Authors: Meghan Jobson, Christine Celestino, Peter Westenkow, Suzanna Gribble, and Stephanie Plamondon, Mark Palfreyman, Maureen Peters, Ph.D., and Margaret Hudson.