In a breakthrough that will give drug developers a target for creating medicine to treat patients with dementia, researchers have for the first time identified a substance in the brain that is proven to cause memory loss.
In the past, scientists thought that plaques and tangles, unnatural accumulations of two naturally occurring proteins in the brain, caused Alzheimer’s disease. But a research team, which included members from the Johns Hopkins University and the University of Minnesota Medical School, hypothesised that there was a specific substance in the brain that causes memory decline that is present even before nerve cells begin to die.
To test that, the team used mice whose genetic make-up was manipulated to develop memory loss much in the way people develop subtle memory problems before the earliest stages of Alzheimer's disease. Using mice that showed early signs of memory loss and had no plaques or nerve cell loss in the brain, they discovered a form of the protein that is distinct from plaques. They extracted this protein and injected it into healthy rats. The rats suffered cognitive impairment, confirming that this protein has a detrimental effect on memory.
Once the memory-robbing protein complex is better understood, drugs could be developed to stop Alzheimer's disease in its tracks, the researchers said. Worldwide estimates of the number of people with Alzheimer's disease range from 15m to 20m.
In the past, scientists thought that plaques and tangles, unnatural accumulations of two naturally occurring proteins in the brain, caused Alzheimer’s disease. But a research team, which included members from the Johns Hopkins University and the University of Minnesota Medical School, hypothesised that there was a specific substance in the brain that causes memory decline that is present even before nerve cells begin to die.
To test that, the team used mice whose genetic make-up was manipulated to develop memory loss much in the way people develop subtle memory problems before the earliest stages of Alzheimer's disease. Using mice that showed early signs of memory loss and had no plaques or nerve cell loss in the brain, they discovered a form of the protein that is distinct from plaques. They extracted this protein and injected it into healthy rats. The rats suffered cognitive impairment, confirming that this protein has a detrimental effect on memory.
Once the memory-robbing protein complex is better understood, drugs could be developed to stop Alzheimer's disease in its tracks, the researchers said. Worldwide estimates of the number of people with Alzheimer's disease range from 15m to 20m.