mouse can't communicate with my iMac

my keyboard's in my mouse do not move the cursor on screen. I tried the Apple Bluetooth keyboard and mouse, hey wireless keyboard and mouse, in even a wired trackball. Nothing will register and I can't communicate with my iMac. Otherwise, when I turn it on it looks like everything else is fine. It didn't seem to be running very hot yesterday, that may have had something to do with it. Does anybody have a suggestion on how I can get this fixed?