The brains of mice that Bradley Hyman keeps in his sprawling lab at an old naval base in Boston offer a window, literally and figuratively, into the mysterious damage that causes Alzheimer's disease. When each mouse reaches a few months of age, one of the lab workers carefully creates an opening in its skull and places a tiny glass window over the hole. Day after day, week after week, a powerful microscope is trained on the brain, searching for ugly clumps of sticky protein fragments like those that litter the brains of elderly people who have died of Alzheimer's. "It's like time-lapse photography," says Hyman, director of the Massachusetts Alzheimer's Disease Research Center at Harvard Medical Schoo. When the ugly plaques appear - and they always do, as the mice carry genes engineered to produce them - nearby brain cells begin to wither and die, interrupting the flow of information. Next, waves of cells die off.
Hyman's microscope is one of several new technologies that promise to revolutionize the struggle to understand and beat Alzheimer's, which now afflicts more than 5 million Americans. Worldwide, a staggering 1 percent of all economic output is spent caring for and treating people with it and other types of dementia, according to Alzheimer's Disease International, the umbrella group of Alzheimer's associations around the globe. Meanwhile, just four drugs have been approved by the Food and Drug Administration to battle the disease, and all address symptoms only, not the poorly understood causes. Over the past decade, billions of dollars have been poured into researching drugs after initially-promising drug, and nearly all have been disappointing in large clinical trials.