Actually, these rodents are good models to study, but I love the reporting when when a new finding emerges, such as this one:
Scientists at McKnight Brain Institute of the University of Florida say (or at least their public relations reps say) "People don't have to run marathons to keep their brain cells in shape - regular, light activity may do the trick. In the first study to show that lifelong exercise decreases cellular aging in the brain, scientists say that moderately active rats have healthier DNA and more robust brain cells than their less active counterparts." In just one sentence we moved from rats to people - both with "regular, light activity" with improved brain cell activity.
The research was presented at the Society for Neuroscience's 35th annual meeting.
I do love this quote from one researcher: "The difference between humans and rats is that it isn't as easy to get humans to exercise. Put an exercise wheel in a rat cage and a rat will zoom around on that thing all the time, unless it's sleeping. But putting an exercise machine in your family room doesn't mean you're going to use it."