From the article:
The UNC scientists treated those mice and others whose genes were functional with a toxin called cuprizone that slowly stripped away the myelin coating on nerves in their brains and then observed myelin regeneration indicative of nerve repair. Normal mice recovered completely, but those lacking the functioning tumor necrosis factor-alpha gene did not, which indicated how critical the protein was to the repair process.
“We’ve found that these tumor necrosis factor molecules are very important for the white matter in the brain to repair itself,” Ting said. “White matter is part of the brain that allows motor skills, and if you don’t have it, you can’t move.”
“We further found that the repair process acts through a particular pathway that appears to induce the production of nerve precursor cells,” Arnett added. “Those cells will eventually differentiate into oligodendrocytes – cells that make myelin and surround nerve axons.”
Recent clinical trials of several drugs designed to block the alpha form of TNF, which was considered to be a problem, actually made patients’ conditions worse, Arnett said. In part, the UNC experiments were designed to find out why.