One of the suspected culprits in the devastation caused by Alzheimer's disease is a substance known as beta-amyloid protein. Scientists know that this protein forms lumps inside the brain that are associated with memory loss, senility, and death. They've also found gene mutations in people with inherited Alzheimer's that lead to beta-amyloid production.
Now, an unexpected finding makes the story more complex and offers a new route to Alzheimer's drugs. Scientists at Harvard Medical School and Athena Neurosciences Inc. report in Nature magazine that beta-amyloid is made by normal blood vessel and brain cells, not just those of Alzheimer's victims. As a result, says Harvard neurologist Dennis Selkoe, the disease may be caused by either excessive production of the protein or an inability to remove it. In either case, Selkoe suggests, drugs that cut levels of the protein might be effective therapy. And newly discovered cultures of beta-amyloid-producing cells offer a good method for screening such drugs.