Swiss researchers say there is evidence that prions play a vital role in the maintenance of the sheath surrounding our nerves.
They say it is possible that an absence of prions causes diseases of the peripheral nervous system.
One expert said there was growing evidence that the prion had a number of important roles in the body.
As well as the latest research in the journal Nature Neuroscience, other studies have indicated prions may protect us from Alzheimer's disease or even play a role in our sense of smell.
The prion protein only came to the attention of scientists in recent years as they searched for the cause of vCJD - the human variant of BSE, or Mad Cow Disease.
This degenerative and incurable brain condition is now thought to be caused by a "mis-folded" version of the prion. However, there is still little understanding of what the protein is supposed to do in its normal, healthy, form.