Neuron 60, 598–609 (2008)

Studies of Creutzfeldt–Jakob disease (CJD), of which 'mad cow' disease is a form, have suffered from a lack of suitable animal models. A newly developed mutant mouse could reinvigorate the field.

To create it, Roberto Chiesa of the Mario Negri Institute for Pharmacological Research in Milan, Italy, and his colleagues expressed a disease-associated variant of prion protein (PrP) in mice. The mutant mice exhibited all the classic symptoms of CJD, including a lack of coordination, accumulation of PrP aggregates in the brain, memory loss and abnormal electroencephalographic and sleep–wake patterns. Previous models of CJD have replicated only the motor effects of the disease.