Why mice are the best candidates for research

(Inside Science) -- The mouse ... this tiny creature has had a huge impact on science research. Mice make excellent models for human disease because parts of their DNA are similar to human DNA. They suffer from many of the same ailments as humans, such as cancer, diabetes and even anxiety. Research on mice has helped scientists understand the causes of many different diseases -- and the use of brain imaging with mice has been a big boost to studies of brain function in humans.

But mice brains are tiny, and guess what? Imaging a little brain for research isn’t easy. Now scientists may have found a better, easier way to help further research.

To some people, this might be considered a pesky pest, but to Adam Bauer, at the Washington University School of Medicine in St. Louis, this little creature is an amazing research tool.

"The beauty of imaging mouse models or even rat models or monkeys or people is that all of us, all mammals have hemoglobin in their brains,” said Bauer.

Hemoglobin is the molecule in blood that carries oxygen. It makes it easier to take an image of the brain because it works as a good contrast agent during a functional MRI scan -- helping to light up certain parts of the brain.

“That’s something that we can all image, from humans all the way down to mice. And the fact that mice exhibit these functional networks that resemble very closely to what we see in people is really powerful,” said Bauer.

Just like doctors use functional MRI -- or FMRI -- to look at human brain activity, Bauer uses a similar technique -- but for tiny mouse brain activity. The technology shows which area of the brain is in use during a particular mental process while a mouse is awake.

“What we develop is kind of an FMRI surrogate for use in mice. So, up until recently, FMRI was having a pretty difficult time creating really nice images in the mouse brain using the standard techniques that they use in people. It’s come a long way and they’re able to generate some really beautiful images now, looking at changes in the blood activity in the brain,” said Bauer.

“The mice will be brought into our imaging systems and we’ll image their activity, they’ll be very specific behaviors that we will have these mice perform or specific tasks that we’ll have these mice perform. So, certain regions of the brain are responsible for the execution of specific tasks,” said Bauer.

Bauer also looks at the brains of mice that have been given a stroke. Researchers can learn how the mouse brain works to restore functional areas and remap itself to compensate for the damage from a stroke -- and translate those results for restoring more function in humans.

“And so, by imaging mice, you can learn a lot about human disease and how to affect it and treat it and make it better in people,” concluded Bauer.