Researchers studying the development of human embryos may have shed light on the neurochemistry of Alzheimer's disease. When the brain and spinal cord are being formed excess nerve cells are generated that have to be removed to refine the pattern of nerve cell connections. Scientists from the U.S. biotechnology company Genentech found that the substance amyloid precursor protein (APP) is behind this process. APP is also found in the brain plaques characteristic of Alzheimer's disease and the scientists thought that it plays a part in killing healthy brain cells in people with the condition.
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