Brain Protein’s Role Linked to ‘Mad Cow Disease’ Symptoms

Japanese scientists have found an important role played by a brain protein linked to “mad cow disease” and a related human illness. Bacteriologist Shigeru Katamine of the Nagasaki School of Medicine reported in the April 11 issue of Nature that mice genetically bred so they did not have the proteins, called prions, showed symptoms markedly similar to the deadly brain infection and the human equivalent, Creutzfeldt-Jakob disease.

The genetically engineered mice developed normally until the age of 70 weeks. “But at about 70 weeks old, all the [mice without prions] without exception became easily identifiable by their abnormal gait,” Katamine’s group wrote. The symptoms got worse as the mice got older. In “mad cow disease,” the prions are mutated into an abnormal form.