A newly developed microscopy technique allows for the first tim, visualising more than 30 protein markers simultaneously in the human brain and to use bioinformatics to analyse their spatial relationships. In the process, the researchers have discovered a previously unknown population of immune cells in the brains of Alzheimer’s patients, which is found almost exclusively in the vicinity of a specific type of pathological protein deposit. The newly developed method could, in future, bring about lasting changes not only in Alzheimer’s research but also in the investigation of tumours and other diseases. The research findings have just been published in Nature Neuroscience.