The causes and effects of TSEs have been very strange and difficult to understand. Even harder was for scientists to discover that there was a different kind of infectious agent, the prion protein. Just consuming some meat of an infected individual can give an animal a TSE. The prion protein infects the brain cells and destroys them making the brain look very “sponge like”, before killing the animal. Transmissible Spongiform Encephalopathies have presented many challenges to the scientific profession and will continue to do so for a long time.