A Soviet scientist in the late 1920s by the name of Sergei Brukhonenko actually managed to keep the severed head of a dog alive. The dog’s head was reportedly connected to a primitive heart-lung machine called an “autojector” (or that’s what the inventor dubbed it). The device supposedly gives the head everything it needs to maintain life. http://www.youtube.com/watch?v=k5yRan-aIyc
As great as science is, I don't think anyone will ever get used to severed heads being alive. Let's keep that in Futurama, and not in the future