In mice models a significant RNA toxicity in the Bergmann glia of the cerebellum together with abnormal Purkinje cell firing and fine motor incoordination. In both DM1 mice and humans, proteomics showed a downregulation of GLT1 glutamate transported secondary to MBNL1 inactivation, leading to glutamate neurotoxicity. On the contrary, the upregulation of GLT1 corrected Purkinje cell firing and motor incoordination in the DM1 mice model. This evidence concerns the gene MBNL1 and myotonic dystrophy type 1.