Long before the onset of dementia, there are signs of increased activity of the brain's immune system. Researchers at the DZNE and the University of Bonn have come to this conclusion based on a study of more than 1,000 older adults. Various proteins were recorded in the cerebrospinal fluid for this purpose: They served as so-called biomarkers that indicate inflammatory processes of the nervous system. As it turned out, some of these molecules are apparently part of an immune system damage limitation program - which could be useful for the development of new drugs. The study results have been published in the scientific journal "Neuron".