Spared nerve injury (SNI) model of neuropathic pain
The neuropathic pain model induced by spared nerve injury (SNI) in rats was performed as previously described. Adult male rats (250 g, Envigo, Placentia, CA) were anesthetized with isoflurane (5% induction, 2% maintenance in 2 L/min air), and skin on the lateral surface of the left hind thigh was incised. Then, the biceps femoris muscle was dissected to expose the three terminal branches of the sciatic nerve. The common peroneal and tibial branches were tightly ligated with 4-0 silk and axotomized 2.0 mm distal to the ligation. Closure of the incision was made in two layers. The muscle was sutured once with 5-0 absorbable suture; skin was autoclipped. Animals were allowed to recover for 7 days before any testing. On the 7th day after SNI, CBD3063 (0.3 µg/kg) or 1% DMSO was injected intrathecally. Mechanical allodynia was assessed 10 days after surgery.