THE PRESENT INVENTION RELATES TO ANTI-MAG ANTIBODIES OR FUNCTIONAL FRAGMENTS THEREOF WHICH COMPRISE A HEAVY CHAIN VARIABLE DOMAIN (VH) WHICH COMPRISES IN SEQUENCE HYPERVARIABLE REGIONS CORH1 AS SET OUT IN SEQ ID NO:4, CDRH2 AS SET OUT IN SEQ ID NO:5, AND CDRH3 AS SET OUT IN SEQ ID NO:6, AND A LIGHT CHAIN VARIABLE DOMAIN (VL) WHICH COMPRISES IN SEQUENCE HYPERVARIABLE REGIONS CDRL 1 AS SET OUT IN SEQ ID NO:1, CDRL2 AS SET OUT IN SEQ ID NO:2, AND CDRL3 AS SET OUT IN SEQ ID NO:3 AND TO PHARMACEUTICAL FORMULATIONS CONTAINING THEM AND TO THE USE OF SUCH ANTIBODIES IN THE TREATMENT AND/OR PROPHYLAXIS OF NEUROLOGICAL DISEASES/DISORDERS.