Bad Prions make Cows Mad but Good Ones just make them Smell

Misfolded proteins called prions are the culprits blamed for such fatal neurodegenerative illnesses as mad cow disease. But, according to new research by electrophysiologist Stuart Firestein of Columbia University, the proteins in their properly folded form are vital to the sniffing skills, therefore survival skills, of animals.

Although the villainous prions have previously garnered the majority of research attention, the normal form of prion proteins is on the rise. Brain tissue is especially high in the proteins, and recent studies have shown that they assist neurons in conducting copper and may even protect them from destruction by rogue chemicals in the body. But until now, no one had tied prion proteins to any particular neurological function such as the sense of smell.

Firestein and his team were studying the sense of smell in mice when they happened to notice unusually elevated levels of normal prion protein (PrPc) in the animals’ olfactory systems. To follow up on the observation, they hid crumbs of peanut butter cookies in the cages’ shredded bedding and timed how long it took both normal rodents and those genetically engineered to not make PrPc to sniff out the treat. The unaltered mice spent an average of 73 seconds to find the cookies, three times quicker than their PrPc-free brethren. According to Firestein, six of the twenty altered mice involved in the study never found the cookies at all.