The preparation and delivery of siRNA were performed as previously described with slight modification.32 (link) Briefly, Scramble RNA (Qiagen, 1022076) or myelin basic protein (MBP) siRNA (Qiagen, SI01302035) was diluted to 200 µM with RNase-free water, aliquoted, and stored at −80℃. Prior to administration, RNA/lipid complexes were prepared by mixing RNA (2 µg) with 8 µl i-Fect™ reagent (Neuromics). After incubating for 10 min at room temperature, 5 µL of the RNA/lipid complex was delivered into the lumbar region of the spinal cord by intrathecal injection. The injection was given daily for three consecutive days.