re: Why hasn't this experiment been done long ago?
Creating useful "artificial gravity" with spin requires a very long radius of spin to do it properly. I don't have the exact numbers in front of me now, but rates higher than a couple of RPM are a problem, and lower is still better.
They will get results from spinning mice at 34 RPM, but probably not what they are looking for. Too bad they won't have a wheel--watching a mouse try to work a wheel with those Coriolis forces would be quite entertaining.
If you put people in that environment, they'd spend most of the day puking.