A study in the October issue of the journal Nature Neuroscience shows that HIV can activate a previously unknown biochemical pathway that leads to nerve cell destruction in the brain, The Wall Street Journal reports. The activation of the pathway could be a major contributor to such HIV-related conditions as dementia, seizures, depression, loss of memory, and loss of motor skills, report researchers from the University of Calgary and the University of British Columbia. The researchers discovered that HIV-infected cells secrete and enzyme, called MMP-2, that converts a key protein in the brain into a nerve-damaging toxin. One of the proteins major roles is protecting the brain from viruses like HIV, which is why brain-related symptoms like dementia tend to turn up late in HIV disease after the proteins are changed, lead researchers Christopher Power says. "MMP-2 is normally relatively quiescent, but HIV turns it on," Power said. Health experts say the discovery could open up the door for new treatments aimed at disabling the biochemical activation pathway, and even possibly new medications for such neurological diseases as multiple sclerosis, Alzheimer's disease, and Parkinson's disease. The researchers warn, however, than any resulting treatments would be at least several years down the road.