Together with colleagues from Stanford University, USA, researchers at the Leibniz Institute on Aging (FLI) have, for the first time, created a comprehensive cell type-specific atlas of lysosomes in the brain, the cell organelles which are responsible for degradation and recycling processes. The study shows that lysosomes in neurons differ significantly from those in other brain cells. Particularly striking is the previously little-noticed protein SLC45A1, which plays a central role in neuronal lysosomes. Mutations in this protein lead to a previously unclear neurological disease that can now be classified as a lysosomal storage disorder.