An international research team involving the Leibniz Institute on Aging – Fritz Lipmann Institute (FLI) in Jena, the Scuola Normale Superiore Pisa, and Stanford University has discovered that in the aging brain, certain proteins are lost even though their mRNA blueprints remain intact. The reason for the loss is not increased degradation, but rather a manufacturing error: ribosomes get stuck on sections rich of basic amino acids, preventing the production of important proteins needed for DNA repair and ribosome assembly. This finding provides new insights into brain aging and neurodegenerative diseases.