fishmike sends this excerpt from a Reuters report: "Scientists have figured out how to stop brain cell death in mice with brain disease and say their discovery deepens understanding of the mechanisms of human neurodegenerative diseases such as Alzheimer's and Parkinson's. British researchers writing in the journal Nature (abstract) said they had found a major pathway leading to brain cell death in mice with prion disease, the mouse equivalent of Creutzfeld-Jacob Disease (CJD). ... Mallucci's team found that the buildup of mis-folded proteins in the brains of mice with prion disease activated a natural defense mechanism in cells, which switches off the production of new proteins. This would normally switch back on again, the researchers explained, but in these ill mice the continued build-up of misshapen proteins keeps the switch turned off. This is the trigger point leading to brain cell death, because key proteins essential for cell survival are not made. By injecting a protein that blocks the "off" switch, the scientists were able to restore the production of the survival proteins and halt the neurodegeneration."