[The fantastic story of the incredible prion].

From the scrapie of the sheep to the bovine spongiform encephalitis, and from the kuru to the Creutzfeldt-Jakob disease, tenacious investigators searched for the mysterious agent of these neurological disorders, till Stanley Prusiner discovered and described the prion in the eighties, wining the Nobel Prize in 1997. But this was not the end of the fantastic history of the incredible protein designed prion by Prusiner, because now the investigation on neuroscience has founded prion-like proteins playing an important role in the genesis of the long-term memory.