Dysfunction of the ubiquitin-proteasome system in the cerebellum of aging Ts65Dn mice

► Proteasome activity is decreased in the cerebellum of Ts65Dn mice. ► The decrease in proteasome activity induces an increase of ubiquitinated proteins. ► Ubiquinated proteins are stored into the nucleus of cerebellar large neurons. ► Neuronal nuclei are intensely stained by FUS immunocytochemistry.