Kathy is right in that Dave Brown is currently investigating manganese intrusion in brain and the effect on the normal form of prion. The fact that CJD victims show a huge increase in post-mortem brain examination (8 to 10 times the normal amount of manganese content) leads one to accept the fact that manganese may indeed create a mutation of the prion protein. By replacing the copper content which is essential to normal prion function, the manganese trips the trigger and causes even the most normal and inactive prion to become the abnormal prion. Dave Brown may well be onto the key to identification of the instances of BSE but we shall have to wait and see where he goes with it. The problem in the UK is the high pollution rate of manganese in certain areas of the country and that may be reason enough to seek out whether or not there were any major BSE clusters that can be linked to the higher polluted areas. Interesting concept.