Scientists first believed that a virus was being transferred in the feed. Then another hypothesis swept over the science field. All mammals carry normal Prp molecules on nerve cells but can get deviant ones by ingesting the meat of animals who carry the BSE disease. The normal prions form open coils, which allow them to be destroyed by protective enzymes if they become damaged. There are still some scientists, however, who remain skeptical of the prion theory.
Some scientists take that one step further.
A research group headed by Sominique Sormaont of the Atomic Energy commission in France did a study in which the brains of cows with BSE were ground up and injected into the brains of mice. After a period of time all mice began to show the physical signs of the disease although fifty-five percent did not have abnormal prions. The researchers leading this experiment speculated that prions are not the agent for BSE, but they probably play a crucial role in how the disease develops. Arguments for and against the prion theory are both very prevalent. Despite the occasional signs of prion being the cause, some critics label the prion theory as demagogy and suggest that BSE is the work of a very crafty virus that has so far eluded detection.