All experiments were performed following the International Association for the Study of Pain guidelines for the Use of Animals in Research, and the experimental protocol was approved by the Institutional Animal Care and Use Committee of Chonnam National University (CNU IACUC-H-2017-10).
Male Sprague–Dawley rats (weight 220–250 g) were acclimated to the laboratory environment for 3 days before use. All animals had free access to a standard rat diet and tap water. The room temperature was maintained at 20°C–23°C with an alternating 12-hour light/dark cycle.
Under general anesthesia with sevoflurane, a polyethylene tubing with inner and outer diameters of 0.28 and 0.64 mm (PE-10 catheter; Becton Dickinson Co., Sparks, MD) was inserted into the intrathecal (i.t.) space through the atlanto-occipital membrane [10 (link)]. The PE-10 catheter was stretched out to reduce the size before use and advanced in a caudal direction until it reached the lumbar enlargement. The other end of the PE-10 catheter was exteriorized to the top of the head and plugged with a stainless-steel wire to prevent clogging of the catheter and later administration of experiment agents. Following i.t. catheterization, the animals were allowed to recover in individual cages for 5 days before further experiments.
Male Sprague–Dawley rats (weight 220–250 g) were acclimated to the laboratory environment for 3 days before use. All animals had free access to a standard rat diet and tap water. The room temperature was maintained at 20°C–23°C with an alternating 12-hour light/dark cycle.
Under general anesthesia with sevoflurane, a polyethylene tubing with inner and outer diameters of 0.28 and 0.64 mm (PE-10 catheter; Becton Dickinson Co., Sparks, MD) was inserted into the intrathecal (i.t.) space through the atlanto-occipital membrane [10 (link)]. The PE-10 catheter was stretched out to reduce the size before use and advanced in a caudal direction until it reached the lumbar enlargement. The other end of the PE-10 catheter was exteriorized to the top of the head and plugged with a stainless-steel wire to prevent clogging of the catheter and later administration of experiment agents. Following i.t. catheterization, the animals were allowed to recover in individual cages for 5 days before further experiments.
