An experimental model for peripheral neuropathy produced by segmental spinal nerve ligation in the rat

Abstract

We attempted to develop an experimental animal model for peripheral neuropathic pain. Under sodium pentobarbital anesthesia, both the L5 and L6 spinal nerves (group 1) or the L5 spinal nerve alone (group 2) of one side of the rat were tightly ligated. For comparison, a parallel study was conducted with another group of rats (group 3) which received a partial tight sciatic nerve ligation, a paradigm developed previously as a neuropathy model. Withdrawal latencies to application of radiant heat to the foot were tested for the next 16 weeks in all 3 groups. Sensitivity of the hind paw to mechanical stimulation was tested with von Frey filaments. The general behavior of each rat was noted during the entire test period. Results suggested that the surgical procedure in all 3 groups produced a long-lasting hyperalgesia to noxious heat (at least 5 weeks) and mechanical allodynia (at least 10 weeks) of the affected foot. In addition, there were behavioral signs of the presence of spontaneous pain in the affected foot. Therefore, we believe we have developed an experimental animal model for peripheral neuropathy using tight ligations of spinal nerves. The model manifests the symptoms of human patients with causalgia and is compatible with a previously developed neuropathy model. The present model has two unique features. First, the surgical procedure is stereotyped. Second, the levels of injured and intact spinal segments are completely separated, allowing independent experimental manipulations of the injured and intact spinal segments in future experiments to answer questions regarding mechanisms underlying causalgia.

Enhanced c‐Fos expression in the central amygdala correlates with increased thigmotaxis in rats with peripheral nerve injury

“…Perioperative analgesia (0.05 mL bupivacaine, AstraZeneca, UK) and antibiotic treatment [Enrofloxacin (“Baytril”): 0.2 mL/kg, Bayer Ltd, Dublin, Ireland] were injected subcutaneously at the start of the spinal nerve transection surgery, which was performed using a technique modified from Kim and Chung (Kim and Chung, 1992; Maratou et al., 2009). A 1–2 cm midline skin incision was made level with the iliac crests.…”

Depressing Interleukin-1� Contributed to the Synergistic Effects of Tramadol and Minocycline on Spinal Nerve Ligation-Induced Neuropathic Pain

“…The L5 spinal nerve was then carefully isolated and tightly ligated with 6-0 silk thread [20]. The surgical procedure for the sham group was identical to that of the SNL group, except that the L5 spinal nerve was not ligated.…”

The Sciatic Nerve Cuffing Model of Neuropathic Pain in Mice

“…Indeed, the sciatic nerve affords relative easy surgery and allows for tests based on paw withdrawal reflexes. The models of chronic nerve compression include for example: the chronic constriction injury (CCI) 4,5 , the sciatic nerve cuffing [6][7][8][9] , the partial sciatic nerve ligation (PSL) 10 , the spinal nerve ligation (SNL) 11 , or the common peroneal nerve ligation 12 . Models referred to as "spared nerve injury" (SNI) are also widely used.…”