4.2. SCI

The rats were anesthetized with 2% isoflurane in 30% oxygen and 70% nitrous oxide. The T9 spinous process was palpated on the top of the back while the rats were positioned comfortably. During surgery, the rectal temperature was maintained at 37.0 ± 0.5 °C using a feedback-regulated heating pad (BWT-100, Bio Research Center, Nagoya, Japan). Skin above the T9 spinous process was shaved and cleaned in an antiseptic manner. T9 laminectomy was performed after a midline dorsal skin incision, which widely exposed the dorsal spinal cord surface. The Infinite Horizon (IH) impactor (Precision System and Instrumentation, LLC., Lexington, KY, USA) was used to induce compression injury with a force of 200 k dynes and a dwell time of zero seconds to the spinal cord. Care was taken to place the rats on the IH impactor table with the spinal cord parallel to it. Following the injury, the delivery of the planned force to the spinal cord was confirmed. The muscles and skin were closed in layers. The urinary bladder was manually emptied twice daily during the first week and once daily thereafter for 20 weeks. One day after the spinal cord injury procedure, two rats showing movements in their hindlimbs were excluded from the study.