Allodynia and hyperalgesia evoked by sciatic mononeuropathy in NKI receptor knockout mice

We have examined the participation of NK1 receptors in neuropathic pain by comparing behavioural responses after partial sciatic nerve ligation in wil d-type (WT) and NK1 receptor knockout (KO) mice. Mechanical responses were tested with von Frey hairs, and cooling responses with acetone. WT and KO m ice showed similar reactions before surgery. Nerve-ligated WT and KO mice s howed equivalent spontaneous pain-related behaviour. Mechanical (mean thres hold 20+/-1 vs 9+/-1 mN) and cold allodynia (6+/-1 vs 14+/-2 behaviours evo ked by acetone) were significantly greater than in sham animals, bur simila r in WT and KO mice. We conclude that NK1 receptors are not essential for m echanical and cold allodynia evoked by partial nerve ligation. NeuroReport 11:1213-1217 (C) 2000 Lippincott Williams & Wilkins.