Neurons are the actors in the brain, transmitting and receiving electrical signals via synapses but they rely on a large supporting cast of cells called glia which help to maintain and nourish them. One group of glial cells called microglia has been implicated in causing Alzheimer's disease. The theory was that microglia reacted to the formation of plaques of a protein called amyloid-beta in the brain by mounting an immune response which in turn led to a toxic release of chemicals worsening the disease. The idea that the inflammation caused by this response by the microglia was behind Alzheimer's has led to a number of trials of anti-inflammatory drugs for the condition none of which proved successful. Researchers at the universities of Florida and Frankfurt looked at the brains of 19 dead people. Some had severe Alzheimer's disease when they died, others a more moderate version and others no disease at all. The researchers found no evidence of any inflammation in the brains of the people with Alzheimer's. However, they did find that microglia were aging and degenerating - just like other cells - something that may lead to the damage to neurons thought to have been caused by inflammation.
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