Intrathecal injection

Under isoflurane (2 vol%) anaesthesia, a dorsal midline incision was made in the lower lumbar region. The L4–5 intervertebral space was exposed by blunt dissection of the tissues. The mouse was fixed by attaching custom-made clamps to the vertebral column. The oligonucleotide solution (1 μL) or PBS (1 μL) was injected into the intrathecal space through a glass micropipette connected to a Hamilton syringe using a dissection microscope. The pipette was retained in the intrathecal space for 5 min after injection and before removal. Finally, the surgical field was irrigated with sterile saline, and the skin incision was closed with wound clips.